AUSTRALIA legend Dennis Lillee believes England's dismal Ashes challenge has been undermined by their failure to prepare properly for the series.

The legendary fast bowler, who is now president of the Western Australian Cricket Association, has begun the build-up to this week's third Test by claiming the tourists did not take their preparation for the Ashes series seriously enough.

Lillee had been expecting a rivalry to match that of 2005 when the two sides met for the current series, rather than Australia racing into a 2-0 lead with victories at Brisbane and Adelaide.

But the 57-year-old believes England's decision to go home for a few days following the Champions Trophy, rather than fly straight to Australia, has undermined their Ashes chances.

"I thought if England had been fully fit and had good preparation there would have been a fight all the way through, but they've had bad preparation," said Lillee, who had 355 wickets in 70 Tests.

"I think going back to England and not coming straight here to get another few days' practice was bordering on stupid - I certainly don't think that will ever happen again."

Lillee accepts England's chances have been hit by injuries but he expects Thursday's Test in Perth to be much closer than the first two.