ENGLAND'S grip on the Ashes looks to be slipping as they closed day three of the third Ashes Test needing an unlikely 557 to win.

Andrew Flintoff's men ended the day in Perth on 19 for one, in reply to Australia's mighty second innings total of 527 for five declared.

Australia had battered England's bowlers, with Adam Gilchrist hitting the second-fastest Test century of all time, from 57 balls.

There were also hundreds for Michael Clarke (135 not out) and Mike Hussey (103), on his home ground.

Meanwhile, it was announced that Ashley Giles is returning from the tour to be with his wife Stine, who is suffering from a potentially serious illness.

The Warwickshire left-arm spinner will be replaced in Englands Ashes Test squad by Middlesex off-spinner Jamie Dalrymple, currently in Australia with the ECB National Academy squad.

England head coach Duncan Fletcher said: "This is very distressing news for Ashley, and the thoughts of all the players and management are with him and Stine at such a difficult time."

Earlier, Gilchrist missed out on breaking the legendary Viv Richards 56-ball hundred against England in Antigua 20 years ago by just two deliveries.

But his incredible 57-ball ton, which included 12 fours and four sixes, was still the second quickest of all time and helped Australia add a huge 408 runs on the third day at Perth.

With their lead extended to 556, Ricky Ponting declared with the score 527 for five.

With Mike Hussey and Michael Clarke also helping themselves to centuries, Australia took an iron-like grip when Gilchrist strode out to the middle with the score already a healthy 365 for five shortly after tea.

He raced to his half-century off only 40 balls but then really accelerated, hitting Monty Panesar for 24 in one over including a sequence of six, six, four, six to finish the over.

With Clarke supporting at the other end, they added 164 runs in 21 overs after tea to shatter what was left of Englands fighting spirit.

Until Gilchrist's innings, England could have counted themselves unlucky not to make further inroads after a combination of missed chances and denied appeals.

Under-fire wicketkeeper Geraint Jones was the biggest culprit by missing a stumping and a catch after Steve Harmison struck in the sixth over of the day to give England a flying start by removing Australian captain Ponting.

But it was a further 17 overs before England struck again as opener Matthew Hayden and Hussey rode their luck to forge an important 62-run stand.

Hussey was fortunate to get off the mark after edging Harmison just short of England captain Andrew Flintoff at second slip, which flew to the third man boundary.

Hayden also enjoyed his share of luck to survive an lbw appeal from Harmison on 65 and then got an inside edge off seamer Matthew Hoggard, which flew just wide of his leg stump to the fine leg boundary.

England believed they should have also dismissed Hussey when he had progressed to 15 when he appeared to have been caught off left-arm spinner Panesar at bat-pad by Alastair Cook only for umpire Rudi Koertzen to reject the appeal.

Panesar finally got his reward for his tight spell of bowling four overs later when Hayden, who was just eight short of his century, got cramped attempting a cut shot and edged to Paul Collingwood at slip, who parried his first attempt before collecting the catch on the rebound.

England should have had a further wicket before lunch but Jones, under pressure for his place after only two half-centuries in his last 26 Test innings, fumbled a stumping chance with new batsman Clarke out of his crease on two.

Jones' miserable day continued after the interval when he also missed Hussey on 48. The batsman mistimed a pull off Harmison and Englands wicketkeeper sprinted 30 yards to square leg to claim the catch from Kevin Pietersen but was unable to take it diving.

Hussey was given one more lifeline when he was dropped on 78 off the first delivery after the drinks break, edging Hoggard to Andrew Strauss in a wide first slip position but again the opportunity was missed.

It enabled Australia's fourth-wicket pair to hammer 60 off the first nine overs with the new ball and enable Hussey to claim his fifth Test century, which included 12 boundaries.

He fell when Panesar was reintroduced, the spinner striking with his third ball when he induced the former Northamptonshire and Durham batsman into an edge behind.

Panesar also dismissed Andrew Symonds cheaply after tea, edging low to Collingwood at slip, but Clarke progressed to his second successive century and was joined by free-hitting Gilchrist in the late onslaught.