If Australia wins in Adelaide, the series could be a whitewash, Shane Warne has declared in his London Telegraph column.
After the comprehensive win in the first Test in Brisbane, the second Test gets under way at the Adelaide Oval on Thursday. The third Test follows in Perth after only a three-day break and Warne believes England cannot win in Western Australia.
"This is the Test which could decide the rubber," he says.
"The second Test of a series is often pivotal. In my last Ashes in 2006-07, it was the Adelaide Test which set us up for the 5-0 win. In 2005, it was the second Test at Edgbaston where the series changed and put England on track.
"England have to win this match because Australia are so strong in Perth.
"Australia's record at the WACA Ground means defeat for them here would not be as disastrous as it would be for England. They would still have time to nose ahead, but if England lose this week, it is all over."
Warne lauded Australia's aggressive approach at the Gabba, saying he believed it had taken England by surprise. The short-pitched bowling, especially from man of the match Mitchell Johnson, and the sledging, were pivotal to the win.
"England will never admit it, but I think they assumed Australia are not good enough," he said. "Now they have had a rude awakening and suddenly, for the first time in a few years, they are in a contest with Australia and that has taken them by surprise.
"It caught England on the hop. They did not rate Mitchell Johnson, and I can understand that given the way he has bowled in previous Ashes, but in recent times he has shown signs of maturing and is bowling as well as we all knew he could."
Warne says England must match Australia's intensity and passion. "Australia looked like they really cared and it mattered to every player."
With Jonathan Trott back in England due to a stress-related illness, Warne professed surprise at England's many issues so soon in the series.
"They should believe they are still the best side in the series and should come out and play well in Adelaide. But I am not hearing that from England. All we are hearing is about issues over sledging, David Warner being nasty and bouncers from Johnson.
"There will be no respite in Adelaide. There will be more aggression and hostility from the Aussies. It is a question of how England cope: so far they have been shocked and seem confused."
Warne believes Ian Bell should bat at three. "He has the perfect technique, is in the form of his life and arguably their best player. He was the difference between the teams in England so why not put your best batsman at three to give him a chance to counter-attack or put the innings back on track if an early wicket is lost."
Joe Root, he said, was "a fantastic young talent" and would be an England player for a long time. "But he would benefit from staying lower down the order, where he can get a feel for the Test game before slowly moving back up again."
Matt Prior needed to put his hand up in Adelaide and volunteer to bat at six, so they can play all-rounder Ben Stokes, or Tim Bresnan at seven and two spinners.
Warne nominated Graeme Swann as another who needed to lift.