England forwards coach Graham Rowntree is backing his pack to dominate Australia's eight in Saturday night's do-or-die clash at Twickenham.
Defeat to the Wallabies would end England's tournament and see them become the first host nation to fail to qualify from the pool stage of a Rugby World Cup.
The dramatic 28-25 defeat to Wales last weekend makes Saturday's showdown a must-win for England.
And Rowntree said: "It was always going to be a big game. It's a pool game against Australia. They're a good team, one of the best in the world.
"We have trained exceptionally well this week. Last week has hardened us. There's been a real focus about what we've done this week. Real focus. We've trained well. We've got to have some composure if we are going to beat one of the best teams in the world."
England's forwards have traditionally had the beating of their Aussie counterparts - Andrew Sheridan, the gigantic Sale prop, famously shredded the Wallabies scrum twice, most famously in the 2007 World Cup in France.
Last November, England's scrum was again too much for the Australians at Twickenham but the Wallabies have since been under the tutelage of the great Argentina scrummager Mario Ledesma, who has seriously improved their technique.
Rowntree said: "There is always an expectation on our forwards to deliver. And rightly so. In any brand of rugby you have got to have good ball for the backs.
"Certainly, Australia, their tight play has really improved. I've been a fan of what they've been doing. I'm a big fan of what Ledesma has brought to that team. They are going to be a real challenge for us.
"I back my guys 100 per cent. You've got to pinch yourselves at how lucky we are, and talk about how blessed we are, rather than being stressed by the pressure of it all.
"You can feel the weight of the nation willing us on. I envy the guys. I remember that feeling as a player."
Former Australia coach Bob Dwyer has claimed that England prop Joe Marler scrummaged at illegal angles, in what was widely seen as an early attempt to get Saturday's referee Romain Poite to keep an eye on the hosts' technique.
Rowntree said: "All that matters is what the officials think at World Rugby, and I've had a good conversation with them this week. And I'm happy with the outcome."
Another former Australia coach, Eddie Jones, said England captain Chris Robshaw was the weak point of the team and expected Australia's Michael Hooper and David Pocock to dominate Robshaw and England at the breakdown.
Robshaw responded: "We drill and train the breakdown every day, Certainly those two [Hooper and Pocock], well those three including Scott Fardy, they are going to be a real threat.
"Our speed to the breakdown has got to be quick to stop what they want to do."