The Wallabies sent a warning to the hosts with a 65-3, 11-try demolition of Uruguay at Villa Park on Sunday.

England are on edge as their tournament hangs dangerously close to disaster following an unexpected loss to Wales on the weekend. Losing to Australia would mean an embarrassing exit from the tournament in their own backyard, while the Wallabies know a win has its own importance to their hopes of World Cup success.

The Wallabies have spent the first two weeks of the World Cup in Bath, removed from the London World Cup bubble and the intensity and scrutiny that goes with it. Their matches against Fiji and Uruguay were hardly show-stoppers and they were always expected to win, but their campaign rises to a new level against England.

"I think we always knew this was going to be a big game [against England] and the lead up in terms of where we were in Bath was going to be different to downtown London," said Wallabies stand-in captain Dean Mumm. "But it was always going to be big. The context might have changed [after England's loss to Wales], but our focus is on ourselves and the improvements we have to make.

"That hasn't changed and we know we have to be better as we go into what is a really important match, regardless of where we are."

England's 2003 World Cup-winning coach Sir Clive Woodward described the match as "our World Cup final". England captain Chris Robshaw has come under fire for his decision to turn down a late penalty opportunity which would have levelled the scores against Wales.

Instead, Robshaw opted to kick to the sideline and go for the win. It's in contrast to the Wallabies' first match against Fiji when stand-in captain Michael Hooper copped some backlash for taking a penalty shot at goal to establish a solid lead rather than going for a four-try bonus point.

"We have to feel sorry for ourselves for 24 hours, take time to grieve and then on Monday everyone has to get up and say, 'right, we have got Australia," Woodward said. "That is a must win, almost with a bonus point. You have to go out there and I just hope they pick an out-and-out attacking team and go for it. Because unless we go out and win this game well, we're out so you have to absolutely go for it.

"You have to cop it, and say well done to Wales. But we are still in the World Cup and Australia now is just our World Cup final. That's it."

Mumm has enjoyed a remarkable week, and it will get even busier when he gets to London and prepares for the England clash.

The veteran lock was made Wallabies captain to play Uruguay in the absence of Stephen Moore from the starting side, rushed to London for the birth of his son less than 48 hours before the game and then scored a try after rejoining the team.

"The head is still spinning, it's been a pretty incredible few days," Mumm said.

"I haven't even held my son yet, so I'm looking forward to getting back to London and doing that, it will be pretty special."

Mumm dismissed concerns the Wallabies were under-prepared for the Twickenham blockbuster given their last three matches have been against the United States, Fiji and Uruguay. "I think the key to that is working hard at training and we've certainly done that whether it was in the US or Sydney or in Bath," Mumm said. "We've worked very hard to put ourselves in a position to attack any game, let alone this one.

"That won't change, we'll recover from today. We'll review early week and focus on the improvements we can get out of it. In terms of being match-hardened, that's what you prepare for and that's what we've been doing."