In a damaging admission that some sources of Tory party funds were "dubious", Lord McAlpine said the party should now act on its promise to hand over the money to the creditors of Mr Nadir's collapsed Polly Peck group if it could be proved that Mr Nadir had stolen it from company funds.
Lord McAlpine, a passionate admirer of Baroness Thatcher, has been alienated from the Tory party for some time, and last year embarrassed John Major by suggesting the party would benefit from losing the next election.
He said that in view of the success the party said it had had in raising money, it could now surely afford to do so.
He added: "I have always said that the Tory party raises money to win elections. If it raises money that could lose it votes, it isn't worth doing."
The Independent on Sunday disclosed that the party was warned three years ago that the bulk of the donation made by Mr Nadir had been stolen from the company.
Lord McAlpine, who was Tory treasurer until 1990, told BBC Radio 4's World at One programme: "At the time we took the donation from Asil Nadir he was regarded as one of Britain's leading businessmen. He had just won the Queen's Award for Industry. Subsequently he turned out to be rather a bad lot. It seems as if the money that we took was dubious. Personally I would have given it back."
A Tory party spokesman said: "We are surprised that Lord McAlpine raises these issues now because he never raised them when he still had strong personal connections with Conservative Central Office."
Speaking from Northern Cyprus yesterday, Mr Nadir said that until the monies were proven to be stolen in a court of law, "there should be no reason for their return".
Lord McAlpine's intervention came as an internal Tory investigation continued into claims that the party had accepted around pounds 300,000 from business people with links to the Bosnian Serb leader Radovan Karadzic, who is wanted for war crimes.
Tony Blair, the Labour leader, is today expected to step up pressure on the Government to agree to a study by Lord Nolan of the whole issue of party funding. Labour's deputy leader, John Prescott, yesterday said the case for the Tories to open up their books to public scrutiny was now "unanswerable" and that Lord Nolan should now be able to mount a full investigation.
"As things stand, a multi-million pound Tory campaign is being funded from secret sources. We have no idea what promises the Tories have given to foreign donors in return for the money. Such a situation is a constitutional outrage," he said.
"The time has come for John Major to reverse his previous decision to deny Nolan the opportunity to investigate party funding. If he refuses, we can only assume that he and his party have a lot of dodgy deals to disguise."Reuse content