Gordon Brown is planning new antisleaze rules for ministers if he becomes Prime Minister in an attempt to restore voters’ trust in politicians, the outgoing standards watchdog said yesterday.

A new code of conduct for ministers, to tighten and clarify rules on conflicts of interest and other areas of controversy, is among measures planned by the Chancellor, said Sir Alistair Graham.

Sir Alistair, whom Tony Blair has effectively sacked as chairman of the Committee on Standards in Public Life, revealed that he had discussed the proposals with Mr Brown in private talks.

“I believe that probably he and his colleagues are working on some sort of package,” Sir Alistair said in an interview for Week In Westminster on BBC Radio 4, to be broadcast today.”

He added: “I know that Gordon Brown is anxious to see that if a minister declares everything when they take up office and they are given a clean bill of health by a ministerial adviser – we currently have Sir John Bourn – then that should be publicly known.”

New rules for ministers would fit with other constitutional changes planned by Mr Brown to restore faith in politics. These include codifying British conventions into a written constitution and giving Parliament the power to vote on whether the Government should go to war. But the Chancellor’s apparent preoccupation with the ministerial code may also be an attempt to protect his allies from attacks by opponents.

Mr Brown was scarred by the forced resignation of one of his closest supporters, Geoffrey Robinson, his first Paymaster General, soon after arriving at the Treasury.

Mr Robinson, a millionaire businessman, was accused of failing to disclose that he was the beneficiary of several offshore trusts. He quit the following year after details emerged of a secret loan of £373,000 he had made to Peter Mandelson, then a middle-ranking minister.

Sir Alistair, who has been forced to step down next month, said that he had urged the Chancellor to make radical changes to the rules ministers must follow, with a short and clear set of principles they must uphold.

He also suggested that there should be independent inquiries into complaints or minor transgressions that merit a warning but not dismissal.

“Gordon Brown, because there has been such a loss of trust between people and politicians, has an opportunity to set a new tone, a new approach to leadership and he would be very foolish to miss that opportunity,” Sir Alistair said.

Meanwhile Mr Mandelson capped a troubled week for the Chancellor by effectively endorsing criticisms of his ruthless style, by Lord Turnbull, the former Cabinet Secretary.

“He [Lord Turnbull] worked closely with Gordon Brown, he was permanent Secretary at the Treasury, he expressed himself from his own experience as he saw it,” Mr Mandelson told al-Jazeera. David Cameron stepped up attacks on the Chancellor, saying that Mr Brown must share responsibility with the Prime Minister for voters’ loss of faith in politics.

In a speech in Bath, the Tory leader said: “I want to make it clear that I regard Gordon Brown to be the natural heir in the art of spin. This week’s Budget proved why. Now that the dust has settled it is becoming clear that the Chancellor has not – as he claimed – delivered a tax-cutting Budget.”

Budget speeches under the Conservatives would be an honest reflection of the measures being announced, with no sleight of hand, he said.

Mr Cameron appealed to Liberal Democrat supporters to back him, saying that he agreed with them on the importance of civil liberties, public services, the environment and the power of local communities.

Sir Menzies Campbell, the Lib Dem leader, will say today: “When I speak to people on the doorsteps they tell me that they see in David Cameron a politician who would say anything to win power.”

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