McGrath has only recently recovered from a long-term ankle injury

England have improved hugely over the last year but McGrath insists that Australia still hold the upper hand.

"Everywhere I go, people are asking me if England can win the Ashes and it is still a year away," he said.

"I've said we could win 4-0, unless we got a bit of rain, in which case it might be 3-0. But it might be back to 5-0 by next summer."

McGrath also told the Guardian newspaper that England should concentrate on the winter tour to South Africa and not on next summer's events.

"The series in South Africa is a big one for England and you should be focussing on that, not the Ashes.

"England are the improving team in world cricket but we have improved since the last Ashes tour.

"Me and Brett Lee have got over major injury problems and Shane Warne's 12 months off have done him the world of good."

England have not won an Ashes series since Mike Gatting's team triumphed down under in 1986-87.

When the teams last met in Australia two winters ago, the home side won the first four Tests before England gained a consolation victory in the final game in Sydney.