Momentum is with England: Gilchrist

England have plunged Australia into a vicious cycle, tourists' vice-captain Adam Gilchrist admitted after the team were left reeling following the second day of the fourth Test at Trent Bridge.

Australia will resume on Saturday on 99 for five in response to England's imposing 477 and a beleaguered Gilchrist said Australia were under extreme pressure as they tried to win a ninth successive Ashes series.

"Obviously the momentum is all with England, it has been for some time now and everything starts to feel like it's going against you," Gilchrist told reporters after stumps on Friday.

"A bit of sloppiness comes into the field, we start missing the odd chance, were not bowling quite consistently in the areas we want to so we can build up pressure and little umpiring decisions you think that might normally go your way go against you.

"All of a sudden it's just a vicious cycle (you're stuck in)," the wicket-keeper added.

"England are doing to us what we've done to other teams for a number of years. It's a challenge for us to be in these scenarios and we haven't come out of it very well so far.

"Mentally it's a different area for us to be in and that's pretty taxing."

But Gilchrist, who will come out to bat on Saturday morning with Australia needing another 179 runs to avoid the follow-on, said the team had not given up hope of retaining the Ashes, with the series currently level at 1-1 and just the fifth and final Test to come after this match.

"We'll just keep fighting. There's still lots of life there and there's still a long way to go. There's no shame in saying that it's a huge challenge. But we'll believe we can get it right at some stage between now and the end of the series and do enough.

"We're not bad cricketers. We've proven that for a long time and we'll certainly hold that very close to us and rely on that to maintain that belief," added the hard-hitting batsman whose team last lost a Test series four years ago in India.

Gilchrist, who vowed to play his natural game on Saturday despite Australia's precarious situation, said the England attack, led on Friday by Matthew Hoggard and Simon Jones, was the best he had faced.

He said it was difficult to work out whether Australia's poor form was their own fault or was caused by England's strong performance.

"We're realising it's the ultimate challenge for us and we're under pressure. But there's no doubt we still believe we can do whatever it takes."

Meanwhile England all-rounder Andrew Flintoff, whose 102 was his first Test century against Australia and the centrepiece of his side's total, warned against complacency setting in.

"We're in a great position," said Flintoff as England chased their first Test win against Australia at Trent Bridge since 1977, the year he was born. "They are 99 for five and we've got runs on the board.

"At Old Trafford (in the third Test where Australia clung on for a draw with one wicket standing) we came desperately close to winning the Test match and we're in a great position here. But we can't get ahead of ourselves."