He told a conference fringe meeting his first act as premier would be to create an independent tribunal to discipline wrongdoing MPs.

Instead of the prime minister deciding whether to sack a wayward cabinet minister, the action would be decided by a new non-political panel.

Mr Davis attacked Tony Blair's habit of rehabilitating disgraced ministers.

'Symbolism'

Pointing specifically to twice-sacked Peter Mandelson and current pensions secretary David Blunkett, Mr Davis said: "There are no long sentences under this government at all, least of all with ministers."

His proposal to create a conduct tribunal would be the symbolic equivalent of Gordon Brown's decision to give independence to the Bank of England in the immediate aftermath of Labour's 1997 election victory, he added.

"It would be a massive piece of symbolism to give back to the British people a degree of trust in politics," he said.

He would also plan a "dramatic change in the powers of parliament" and drastically cut the number of special advisers currently employed by ministers.

Mr Davis held out the prospect of a Conservative government reversing Chancellor Gordon Brown's �5bn raid on pension funds which, he said, was responsible for the current pensions crisis.

However, he said he could not make a definite pledge because he would first have to review the full extent of the damage done by the cut and whether it would be practical to reverse it.