Ben Cohen has told England to forget about their rankings slump when they begin their World Cup campaign this weekend.

The World Cup-winning wing, who has opted out of the tournament in France to be with his pregnant wife, insists England's IRB world ranking of seventh counts for nothing now meaningful action is set to get under way.

And he has urged Brian Ashton's underperforming squad to draw inspiration from the Greek football team, who came from nowhere to win Euro 2004 against all the odds.

``We were the best team in the world and this time around they're ranked seventh, but that doesn't really mean much going into a tournament like this,'' said Cohen, a fixture for Sir Clive Woodward's champions four years ago.

``There are effectively seven one-off games, and anything can go. Look at Greece in Euro 2004, they won when no-one gave them a cat in hell's chance.

``It only takes a few wins and before you know it you are in the World Cup final.''

England get their bid to retain the Webb Ellis trophy under way tomorrow against the USA, with few people giving them a chance of success.

One criticism levelled at Ashton's men is that they lack a leader like Martin Johnson, the peerless lock who captained England in Australia.

But Cohen - who is currently embroiled in a dispute with club side Northampton after his walkout in protest at being overlooked for the captaincy - insisted: ``You can't under-estimate (current skipper) Phil Vickery, and Martin Corry was a good captain too.

``There are a lot of leaders in that side, and that's what you need.''

He added: ``They are going there with the goal of winning the tournament, and rightly so.

``They are more than capable of doing that.''

Cohen believes England are ready to silence their many vocal detractors, and is adamant they will relish their status as underdogs for the title.

``People are under-estimating England a little bit,'' Cohen told PA Sport.

``We'll do well in the World Cup and we always like the fact we're underdogs. The pressure is off you and on the other side.

``If I was in their position I would be pretty happy with where people think we are going to get to.''

He added: ``They are a decent side and hopefully can do the business.

``They've got world-class goal-kickers, they know how to run a game, they've got big forwards and quick backs, and once they link that, which we've seen glimpses of, they are pretty much unstoppable.

``They will be better than people think.''