Simple equation for England: lose to Australia and you're out

By Mike Collett-White LONDON (Reuters) - The permutations of Rugby World Cup Pool A may seem complicated to the three teams still in with a realistic chance of progressing to the knockout stage, but for hosts England one thing is clear: lose and you're out. That would be pressure enough for a country in danger of becoming the first main host nation to exit at the group stage. Add to that the fact that they face old rivals Australia and Saturday's game could hardly be bigger. The match at a packed and impassioned Twickenham will be the biggest between the two teams since they met in the quarter-final of the 2007 edition, when England squeezed through 12-10. After England's 28-25 loss to Wales at the same venue last week, a win against Australia would make them favourites to progress, with a final Pool A game against Uruguay in Manchester on Oct. 10. For Australia, victory would ensure their passage to the quarter-finals even before they meet Wales, currently heading the group, also next Saturday. England head coach Stuart Lancaster sought to remind his team, and country, that they had bounced back from adversity before. "I have been in this position before, and so has the team, in getting over a defeat and turning the next performance into a positive one and a victory," he said. "I know we can do it again. I'm 100 percent certain we can." His Australian counterpart, Michael Cheika, concedes that home advantage could give England the edge. "We are going to have to improve on the first two matches to be able to compete with England," he said. "England are the home team and they are going to be the favourites." England have won four of the past five meetings between the two teams, though their World Cup meetings have a habit of being desperately close. England beat then hosts Australia 20-17 in the final in Sydney in 2003 with a last-ditch drop goal from Jonny Wilkinson settling the match. Australia edged England in the final at Twickenham in 1991, prevailing 12-6. Were England to lose on Saturday, it would be the first time they have gone out at the pool stage. Little wonder Lancaster is telling his players they face the "biggest game of their careers". (Editing by David Goodman)