Rob Kearney believes beating England tomorrow will enable Ireland to claw back some credibility from a disappointing RBS 6 Nations.

The Irish will endure their worst championship since 1999 if they are brought to heel at Twickenham with defeat potentially spelling the end of coach Eddie O'Sullivan's reign.

A poor Six Nations compounds a miserable season that reached its nadir at the World Cup and Kearney is determined to set up the summer tour with victory over England.

Ireland - who start with Geordan Murphy at full-back tomorrow after the Leicester star passed a fitness test on his Achilles injury - play New Zealand on June 7 and Australia a week later.

''There is a sense that beating England will right a lot of the wrongs of this year's Six Nations,'' the Leinster winger said.

''Beating England at Twickenham is a formidable challenge and when it's a great achievement when you manage it.

''Winning would mean we've finished the Six Nations on a high and give us a boost before the summer tour.

''On paper there's nothing left to play for, but inside we all know there's a huge amount to play for.''

The battle for third place is also a poor reflection on England's Six Nations campaign.

Beaten World Cup finalists just five months ago, they have struggled woefully with last Saturday's appalling 15-9 defeat their lowest point yet.

Coach Brian Ashton also finds his position under growing scrutiny that will only an emphatic victory over Ireland will diminish.

But Kearney believes England will be fired-up by their desperation to atone for their horror show in Edinburgh.

''There's no doubt that England losing to Scotland has made our job a whole lot harder,'' he said.

''Nobody ever likes losing at home. We felt that ourselves against Wales on Saturday. It's a rotten feeling.

''England will be determined to right the wrongs of Scotland and win at Twickenham. It should be a tight game.''

Wingers Lesley Vainikolo and Paul Sackey have been retained by England and Kearney has the utmost respect for the duo.

''They're both formidable operators - fine players with a dangerous combination of strength and speed,'' he said.

''I've marked Sackey before and know how tough he can be, so I'm looking forward to it.''

Sackey in particular will have his hands full as Kearney, who will win his sixth cap tomorrow, has been in fine form during his first Six Nations.

The Leinster back was one of the few positives to emerge from the ruins at Croke Park last Saturday with his appetite for work catching the eye.

He added: ''I'm satisfied with the way I've been playing but this is another week and the old clichi that you're only as good as your last game is so true.''