SYDNEY - Australia are vowing no let-up as they chase an Ashes clean sweep against troubled England, who have been forced to re-jig their line-up after the shock retirement of Graeme Swann just days before the fourth Test in Melbourne. The off-spinner -- sixth on England's all-time list of Test wicket-takers -- on Sunday dropped a bombshell when he announced his immediate departure from international and first-class cricket, with the home side 3-0 up in the five-match series.

Little has gone right for England Down Under. The tourists arrived in Australia as favourites just months after winning the Ashes 3-0 on home soil but lost them inside 14 playing days -- stunned by the home side's aggressive approach. Swann's abrupt exit follows batsman Jonathan Trott's return home with a stress-related illness after the first Test and major questions hang over the form of senior players -- captain Alastair Cook, Kevin Pietersen, Jimmy Anderson and Matt Prior.

Swann pointed to internal problems, saying: "Some people playing the game at the minute have no idea how far up their own backsides they are. It will bite them on the arse one day and when it does I hope they look back and are embarrassed about how they carry on." England are battling to avoid a repeat of the 5-0 Ashes whitewash in Australia in 2006/07 following heavy losses in the first three Tests in Brisbane, Adelaide and Perth.

Darren Lehmann, who has masterminded Australia's dramatic turnaround after their defeat in England in July and August, wants his team to go for the jugular in the match starting on Thursday. "I only worry about us. That's how we deal with it and that's all we can do," Lehmann said. "I'm sure they weren't worried about us last time either (when Australia lost in England). They have a good coach and good support staff -- I'm sure they'll work through all those issues. Our point of view is to play the brand of cricket to win us cricket games and obviously it has been quite aggressive out there from both sides. It's good, hard Ashes cricket." Left-arm spinner Monty Panesar is expected to replace Swann for the Melbourne Test, in front of an anticipated world record first-day crowd. The current record of 90,800 was set in the 1961 Test between Australia and the West Indies.

Panesar suffered in the second Test in Adelaide, where England played two spinners, returning combined figures of two for 198 and he will come under pressure from the Australian batsmen keen to get on top and dictate. Seamer Tim Bresnan, who took six wickets in the corresponding Test on the 2010/11 tour as England retained the Ashes, admitted it will be tough halting Australia's momentum. "As soon as a side gets in front there's virtually no way back," he said.

"We have pulled off some special comebacks over the years but against this team right now, they're going for the jugular straight away, which was what we were doing (to them) last summer." Bresnan also voiced support for under-fire team coach Andy Flower, who has refused to confirm he will remain in charge of England beyond the Australian tour. "Regardless of what happens over the next six to eight weeks, Andy is the man to take us forward," Bresnan said.

"The things he's achieved with this team, from the outset when he joined us, is staggering when you consider the record of how England have played cricket over the last 30 years. He still cares as much now as when he first took over - in fact probably a little bit too much at this moment in time, because things aren't going as well as they usually do. But it's up to the players to put that right, the 11 on the field, not the coach," Bresnan said.

England have won four of the past eight Ashes Tests at the MCG and three years ago beat Michael Clarke's team by an innings and 157 runs. While the tourists are considering changes, with wicketkeeper Prior under pressure, Lehmann said it was likely Australia would name an unchanged eleven for the fourth straight match.