Alastair Cook will ask his England team to look into their ''inner souls'' in defence of the Ashes, after their second successive landslide Test defeat.

Cook's tourists trail 2-0, with three to play, having lost in Adelaide by 218 runs - and will therefore need to overturn 77 years of history to recover from such an unpromising position and prevail after all this winter.

Even retaining the urn via a drawn series is a distant prospect, after Mitchell Johnson again dismantled England's batting here in his second consecutive man-of-the-match performance.

England head next for Perth, where Johnson underpinned Australia's sole victory against them on the last tour three years ago.

Cook retains hope that his team can battle back there, but acknowledges an honest reaction to evident failings so far must be the starting point.

''We have to look hard into ourselves, deep into the inner soul and drag the performance out of ourselves,'' he told Sky Sports 2.

''A 2-0 lead is not insurmountable.

''It's a bit like football - if we get the next goal, it's vital.

''We can't mope about feeling sorry for ourselves. We have to hold our hands up and say we haven't been good enough.

''We have to drag the runs out of ourselves, drag the wickets out of ourselves.''

England lost their last four wickets in almost exactly an hour on a dank final morning at the Adelaide Oval, despite a return to form for Sussex's Matt Prior (69).

They were bowled out for 312 - 133 runs more than they had managed in any of their three previous attempts here and at the Gabba - in a match lost first of all when they failed to hold their chances as Australia piled up 570 for nine declared and then to Johnson, who took seven for 40 in the first innings.

Cook warned that England themselves must retain belief, even if others do not on their behalf.

''We've had a big hit - and if we believe that the Ashes are gone, they might as well be gone,'' he said.

''We've had two tough games and we haven't played well. That's the simple deal.

''We have to dust ourselves off and do what we can do, which is work bloody hard on our games and come out to Perth on Friday with that belief that we can do something.

''We need to put some pressure back on Australia.''

Cook appears mystified at England's frailty in the first two Tests, after last summer's 3-0 win at home over Australia.

''I don't know what's quite gone on these couple of games,'' he said.

''We feel we're doing the right things, but at the moment our skills in the middle are letting us down.

''The only people who can change that are the 16, 17 players in the dressing room.''

He knows the primary responsibility is his, as captain and opening batsman - after a double failure here at the top of the order against Johnson.

''I've got to step up as a batter and score more runs,'' he said.

''Everyone has to.

''What we do know is that side has got a lot of talent, a lot of skill - and has proven that over a long period of time.

''We have to hold on to that.

''We are very good players in that dressing room, but you can only say that for so long - and we have to start delivering.''

Peter Siddle (four for 57) and Ryan Harris (three for 54), rather than Johnson, completed the job for Australia in the second innings.

Cook's opposite number Michael Clarke, meanwhile, refused to crow about his team's two easy victories.

''It's still the hardest game it the world,'' he said.

''It's enjoyable, there's no doubt about it. The thing that's most pleasing is we're finally getting the results.''