Hello and welcome to ESPNF1's coverage of the Hungarian Grand Prix, and the weather in Budapest is wet. There was a wet/dry/wet race earlier in GP2 and it delivered an amazing race with the winner coming through from 21st on the grid, and second place coming through from 24th. More of the same would be ideal.

The cars are heading to the grid as I type, and it's drizzling with rain. Felipe Massa went off the track at turn four on his way to the grid as the track is very wet off-line, and the kerbs and painted lines are very slippery.

Pirelli's Paul Hembery tells the BBC he'd go with "inters for sure", and says they will last for 20 laps. With 20 minutes to go to the start of the race though, if the drizzle stops we'll be closer to a dry track by the time the lights go out.

Images show that the weather radar is telling the teams that the start of the race will see light rain. Jenson Button also confirms to the BBC that the track isn't that wet but it is very slippery.

So these conditions could shake up the race order, and calling a winner has become very hard. If you're feeling brave enough to predict the victor, you can let us know via the email link above or by sending us a tweet on Twitter @ESPNF1_live.

It's very grey all around the circuit, and the rain seems to be getting slightly heavier, with further bands visible on the weather radar. This is going to be a tough call for the teams because the ever changing conditions mean there's a chance they could switch to slick tyres and then further rain dampens the track again.

Williams (WilliamsF1Team) on Twitter: "It's still raining!"

Christian Horner tells the BBC that he is worried about Hamilton, Button and Alonso, and that the race will be one of the hardest to call from the pit wall. It's interesting that he mentions Alonso, because the cool conditions didn't help Ferrari last weekend and it's only 18C track temperature again today.

The rain continues to fall, but there's still a relatively dry line on the left hand side of the grid compared to a wet right hand side. That means the odd-numbered grid slots will expect to get a better start than the even, so Vettel's biggest threat in to turn one could come from Button behind.

Steven asks: "Quick Question... are full wets the same compounds as intermediates or a bit softer? If they're softer, I'd love to see someone like Rubens gamble and storm through." To be honest Steven we're not sure of the details, but they're likely to be different compounds. Their aim is to move water though, so the large difference in treads negate the difference.

All cars are on intermediate tyres as they complete the warm-up lap, and Nico Rosberg runs wide at turn four looking for the limits of the track grip.

The grid is forming, and the lights are on...

Lap 1

Vetetl gets away cleanly, the McLaren's are side by side but Hamilton takes the karting line around turn two and holds the position. Rosberg with a flyer up to fourth with Schumacher fifth and Alonso sixth. Alonso passes Schumacher for fifth in the final corner.

Lap 2

Grip levels are extremely low, both Hamilton and Vettel get sideways in the first sector and are close together. Button coming back towards the leaders now.

Webber is eighth ahead of di Resta, as Schumacher defends from Massa.

Lap 3

Vettel defends from Hamilton in turn two, while Alonso gets past Rosberg on the exit of turn one.

DRS is enabled, this should be fun....

Lap 4

Hamilton is all over Vettel, and gets up the inside in to turn two but Vettel hangs it around the outside of the corner and defends well. Alonso close to Button but then runs wide in turn two and loses a place to Rosberg.

A dry line is appearing, and the gap from Vettel to Button is 2.2s

Lap 5

Vettel goes wide in turn two and Hamilton leads, Button all over the back of the Red Bull now. Rosberg still holding up Alonso.

Lap 6

Hamilton pulls out 2.4s in the space of a lap.

Fights all the way down the field as Petrov and Buemi scrap over 11th in to turns one and two.

Schumacher is told the rain threat is reducing and there will be no more rain in 20 minutes.

Lap 7

Alonso runs wide at turn 12 and Massa gets ahead, but Alonso retakes the position in to turn one using the DRS.

Schumacher has dropped to eighth with di Resta on his tail.

Lap 8

Hamilton is flying, comfortably the fastest man and his lead is up to 4.5s over Vettel. Alonso is next quickest and is all over the back of Rosberg.

Massa spins off at turn two after touching the white line, and nudges the wall but keeps the engine running and rejoins in ninth behind Di Resta.

Lap 9

Hamilton with another fastest lap, he's in a race of hs own at present and extends the lead to 5.4s. Vettel has 1.7s over Button and is told he can pit whenever he wants as he has a gap behind to come out in to.

Alonso uses the DRS and a karting line around the outside of turn one to pass Rosberg for fourth place. He then sets the fastest first two sectors of the race...

Lap 10

The weather radar says no rain expected in the next 30 minutes but drops are possible from time to time. Alonso sets the fastest lap as Ferrari come out in to the pits with slick tyres as Rob Smedley tells Massa they could take a risk from their current position.

Vettel matched Hamilton for the first time on the last lap, and Alonso is the quickest man on the track.

Lap 11

Vettel sets the fastest lap, 0.5s quicker than Hamilton as Alonso then goes 0.2s quicker. Hamilton responding on this lap.

Webber and Massa pit for slick tyres. Everyone will be watching their times with great interest and there's no drive out of turn one.

Lap 12

Button pits for soft tyres, and he rejoins in clear air but struggles to get the power down out of turn one as well.

Webber gets past a Toro Rosso easily.

Lap 13

Hamilton, Vettel and Alonso all pit. Rosberg does too but Schumacher stays out and passes Hamilton for the lead. Webber does the fastest lap so the slicks are the best tyre now.

Hamilton passes Schumacher in turn 13 and then Schumacher pits.

Lap 14

Button sets the fastest lap and then passes Vettel up the inside in to turn two.

Webber passes Alonso on the exit of turn one - getting the slicks up to temperature has really helped those who pitted first. Massa then sets the fastest lap. He also pitted early.

Lap 15

Hamilton with the fastest lap and he leads Button by 5.2s. Vettel is told not to overlap brake and throttle as he tries to keep pace, and Webber runs wide in to turn one but Alonso isn't close enough to profit.

Maldonado is handed a drive through for speeding in the pit lane.

Lap 16

Hamilton with another fastest lap to extend his lead to 6.9s, while Button has Vettel for close company.

Massa had a delayed pit stop and is ninth behind Schumacher. Di Resta is up to seventh and match Rosberg's pace.

Lap 17

Webber has Alonso close behind as everyone has their tyres up to temperature now. Alonso sets the fastest lap, he's 16s off the lead in fifth place.

Lap 18

Hamilton responds with a much faster lap, 1.7s quicker than Button and almost 2s quicker than Vettel. Gap up to 8.6s.

Lap 19

Massa is all over the back of Schumacher now and is told he has his DRS available despite a damaged rear wing. Di Resta still catching Rosberg.

Lap 20

The radar says steady rain expected in ten minutes, as Button sets the fastest lap of the race.

Trulli retires at the start of the pit lane, he's the first man to drop out. His team-mate Kovalainen is up in 15th place having a strong race.

Lap 21

Hamilton sets another fastest lap, as Button pulls out 1.6s on Vettel who is now over 10s off the lead. Webber and Alonso are catching Vettel and are now less than 7s behind.

Lap 22

Webber with the fastest lap and he takes 0.8s out of the gap to Vettel, who responds with a fastest first sector.

Di Resta now 2.6s behind Rosberg, and over 3s ahead of Schumacher who continues to hold up Massa.

Lap 23

Button quickest of the leaders on the last lap. Vettel is 2.5s behind him now, and still slipping back towards Webber

Lap 24

Button takes 0.5s out of Hamilton's lead, down to 7.7s now, and Hamilton complains of tyres overheating. His race engineer tells him to use the wet patches to cool them down. Button takes 1.4s out of his lead with a new fastest lap of the race.

Lap 25

Heidfeld pits but as he rejoins the car catches fire on the left hand side. It appears to explode slightly and has left a big mess on the inside of the pit exit.

Lap 26

Webber and Alonso pit, as well as Massa as they anticipate a possible safety car. Heidfeld's car is smoking heavily still but the safety car stays where it is.

Lap 27

Hamilton pits too, but Button stays out as does Vettel. Replays show Heidfeld jumping out quickly, and the engine giving up.

Lap 28

Still under yellow flags as Button pits. Vettel now leads from Hamilton. Alonso is the quickest man on track but has fallen 3.4s behind Webber.

Schumacher retires, parking the car after a spin. We'll look to find out the exact cause.

Lap 29

Vettel pits but as he exits the pit lane marshalls are dragging Heidfeld's car the other way, which will have been distracting. The green flags are out now, as we see a replay of Massa passing Rosberg, who is on the soft tyre rather than the supersoft.

Lap 30

Button quicker than Hamilton on the last lap, but the gap is still 7.3s. Vettel is 2.8s ahead of Webber with Alonso a further 1.5s back.

Kobayashi has yet to pit for the second time and finds himself up in sixth place ahead of Massa, Rosberg and di Resta.

Lap 31

Webber and Alonso close together and edging towards Vettel. The gap now 2.6s.

Perez is under investigation for overtaking Kovalainen under yellow flags.

Lap 32

Vettel responds to the pressure around him with an extremely quick lap. Fastest lap of the race and 1.4s quicker than anyone else.

Perez gets a drive through penalty.

Lap 33

Vettel the quickest man on track now. He takes a second out of Button on the last lap and 1.3s out of Hamilton. He's within 5s of Button and the same margin ahead of Webber.

Lap 34

A slow final sector slows Vettel's progress. Webber defends the inside line in to turn one with Alonso using the DRS to close in.

Massa passes Kobayashi in to turn one for sixth. Kobayashi is on the harder soft tyre.

Lap 35

The pace has stabalised at the front, but Webber and Alonso are now 1.5s per lap slower than the front three. It's starting to turn in to a three-horse race unless we have further rain.

Kobayashi puts, releasing Rosberg and di Resta.

Lap 36

Alonso pits for the third time, another set of super soft tyres for the Ferrari. He was getting held up behind Webber.

Lap 37

Perez pressures Alonso as he exits the pits but the Ferrari maintains position. At the front, Hamilton leads by 7.4s with Button 4.8s ahead of Vettel. Hamilton is told over the radio that they want him to go for another nine laps on this set of tyres.

Alguersuari passes Barrichello under braking in to turn one for ninth place.

Lap 38

Unsurprisingly, Alonso setting fastest sectors on his fresh rubber, and sets the fastest lap of the race. He's 2.4s quicker than anyone else on that lap.

Lap 39

Vettel radios in to say that his rear tyres are going away. He's stopped catching Button at the previous rate, and Button has brought the gap at the front down to 5.9s as Hamilton has a slow lap.

Lap 40

Webber pits and puts on the prime tyre. Webber has been jumped by Alonso.

Hamilton very slow, and he pits but is slightly slow getting away.

Lap 41

Another set of supersoft tyres for Hamilton. Vettel is really struggling too, with Button pulling away from him again.

Massa pits again but has a slow stop.

Lap 42

Vettel pits, and Button stays out. Soft tyres for Vettel, and Alonso is through in to third place. It depends how well Alonso can look after his supersoft tyres if he can stay there. Soft tyres might mean Red Bull try to get to the end of the race.

Lap 43

Button follows suit with the soft tyre as he pits. Only Hamilton and Alonso on supersoft. Button rejoins with Alonso just behind him.

Hamilton is quick but he needs to pump in some quick laps and make the most of the supersoft tyres.

Lap 44

Webber is told that Red Bull want him to go to the end of the race on these tyres, so you'd expect the same to be true of Vettel. That's 30 laps for Webber and 28 for the championship leader. Hamilton and Alonso have to pit once more, unless they can somehow make the supersoft tyres hang on.

Lap 45

Vettel passes Alonso for third, and both Button and Vettel are the quickest men on the track on the soft tyres. Hamilton's strategy beginning to fall apart...

Lap 46

Hamilton's lead down to 6.3s, and Button is closing in. Hamilton may have to try to go until the end of the race on these tyres if he wants to stay in the running, but it looks like an error by McLaren. Vettel is the quickest man on track now.

Lap 47

Button told to look after the front left to get to the end of the race. Vettel is 2.9s behind Button and 8.6s off the lead.

IT'S RAINING. Hamilton spins and Button leads. The front three all in a row now.

Lap 48

Nobody pits, but it's raining at the back of the circuit. Alonso pits for prime tyres. Button, Hamilton and Vettel seperated by 1.6s

Lap 49

Replays show Hamilton's spin, he touched the kerb in the chicane and went around. The rain is light and expected to stay that way for 15 minutes, but as it stands it seems to be a race between Button and Vettel.

Lap 50

Varun asks: "Hi, I am interested to know Schumacher exit in this race?" It was a gearbox problem Varun.

The rain intensifies and Hamilton is all over the back of Button as his supersoft tyres keep temperature better than the soft.

Lap 51

Hamilton leads, Button's gone off but is still second. The rain is causing big problems as they're all on slicks. Button and Vettel both went wide in turn two, Vettel goes wide at the last corner again.

Lap 52

Button passes Hamilton down the pit straight, but runs wide at turn two and Hamilton is back through. Such close racing. Vettel really struggling, now 7s off the lead.

Webber and Rosberg pit for inters, as we see a replay of D'Ambrosio spinning in the pit lane and fortunately not hitting anyone or anything.

Lap 53

Hamilton pits for intermediate tyres. He comes out about 5s ahead of Alonso who is on soft tyres. Hamilton loses a second in the middle sector. The stewards then confirm Hamilton is under investigation for the way he spun around in front of di Resta.

Lap 54

Hamilton needs more rain, Alonso is all over the back of him. Webber pits and puts slicks back on.

Alonso cruises past Hamilton in turn four, and Hamilton then gets a drive-through for forcing another car off the track. It's all gone wrong for him in the second half of this race.

Lap 55

Hamilton pits again for slicks, his fifth stop of the day, and he still has the drive through to come. He'll be lucky to salvage fourth place.

Lap 56

Button leads Vettel by 5.5s with 14 laps to go. It appears to be all about nursing the tyres to the end, but Vettel is closing in...

Lap 57

Vettel brings the gap down to 4.6s. Hamilton comes in to the pits for his drive through penalty and rejoins just behind Massa and Webber in sixth place.

Lap 58

Hamilton is now 55s off the lead, having been through the pits six times today. He's straight on to the back of Webber though.

Lap 59

Button responds to Vettel's pace and extends the lead to 6.4s.

Webber passes Massa in to turn one, and then Hamilton dives up the inside in to turn six. Alonso spins in to turn 12, and Massa pits.

Lap 60

Button quicker than Vettel now, with the lead up to 7.1s. They still have to make these tyres last for another 10 laps.

Kovalainen retires.

There's a great scrap for seventh place, Di Resta ahead of Kobayashi, Buemi, Alguersuari, Sutil and Perez.

Lap 61

Hamilton with a new fastest lap, but he's 1.5s behind Webber.

That battle for seventh is now for eighth as Di Resta is away, with Kobayashi struggling. Sutil and Perez aren't actually in the fight as they're a lap down but battling between themselves. Rosberg is cruising up to the back of it in 11th place.

Lap 62

Buemi gets up the inside of Kobayashi, but Alguersuari tries to jump in there too and runs in to the side of Kobayashi and half spins. Rosberg now past Alguersuari and right behind Kobayashi.

Lap 63

Rosberg passes exiting the final corner, then Sutil unlaps himself and Alguersuari gets by in to turn one as well.

Right behind them is the scrap between Webber and Hamilton, and Hamilton dives up the inside in to turn 12 for fourth place.

Lap 64

Button's lead up to 9s, and Alonso 1.6s a lap quicker than Vettel but 13s behind.

Lap 65

Five laps to go and Button is now just managing the gap. It's up to 9.7s as Vettel appears to have settled for second. Alonso takes the best part of two seconds out of Vettel on that lap...

Lap 66

It could be Vettel being cautious, or his tyres could be going off. He has been on them for 24 laps so far.

Lap 67

Webber still close behind Hamilton, and these two will be sprinting to the end on relatively fresh tyres.

Vettel responds to Alonso, losing just the one second on that lap. He has it under control.

Lap 68

The battle for eighth is still going strong, with Buemi and Rosberg less than a second apart.

Webber has now dropped 1.1s behind Hamilton.

Lap 69

I may have spoken too soon on the Hamilton and Webber battle. A fastest first sector from Webber closes the gap to 0.7s. They're coming up behind the battle for seventh between Di Resta, Buemi and Rosberg too...

Lap 70

Vettel does his fastest lap of the race as Button starts his final lap.

Jenson Button points to the crowd and crosses the line to win the Hungarian Grand Prix. Vettel with another quick lap at the end of the race closes the gap to 3.5s, and Alonso comes home third.

Hamilton keeps it together to hold on to fourth, with Webber fifth and Massa fifth. Paul di Resta crosses the line with a highly impressive seventh place ahead of Buemi, Rosberg and Alguersuari.

Button wins on his 200th start and says over the radio "Fantastic going in to the summer break, let's come back and win them all"

At the back, Daniel Ricciardo beats both d'Ambrosio and Liuzzi to 18th place.

Button climbs out on to the top of the car and celebrates at the scene of his first grand prix victory five years ago. He runs around the barriers to celebrate with his team.

Button doing his own version of Vettel's single finger salute, and Vettel congratulates him with "Happy 200th huh!" Vettel smiles as he shakes hands with Alonso, and he'll be pleased to extend his championship lead even further.

Button says "Hi Mum" to the camera before asking Alonso "How was it for you mate?" The response is pretty short, simply "OK".

Button puffs his cheeks and smiles as he stands atop the podium and the British national anthem rings out. He frowns at a rather odd trophy having lifted it above his head.

The champagne sprays on the podium as Button marks his 200th race start with his 11th victory. Sebastian Vettel looks pleased enough as his march to the title continues despite no win in three races. See what they have to say, and get the reaction from the rest of the grid by keeping an eye on the ESPNF1.com website, and thanks for joining us for the live coverage of another fantastic grand prix. Live commentary will be back for the Belgian Grand Prix at the end of August. Bye for now.