A senior Tory has condemned the decision to make the party's controversial treasurer and benefactor Michael Ashcroft a peer amid questions over the appointment process.

Mr Ashcroft, a millionaire business tycoon who spends most of his time in Belize, was nominated by Tory leader William Hague and is included in a list of new working peers published on Friday.

But Mr Ashcroft has only received the peerage after giving what Downing Street said was a "clear and unequivocal assurance" that he would will take up permanent residence in the UK - a condition described as "unprecedented" by former Tory leader in the upper house, Lord Cranborne.

Lord Cranborne described the decision to make Mr Ashcroft a peer as "an affront to the dignity and the standing of the party".

Labour backbenchers have also condemned the appointment, with MP Peter Bradley claiming it amounted to "cash for coronets".

Responding to the news Mr Ashcroft, whose business interests are largely based in Belize, said he was "thrilled and honoured to have become a working peer".

He said: "As a businessman, as a campaigner against crime and drugs, and as a political party fundraiser, there are a number of subjects in which I have both great interest and some experience. I hope to put these to work."

The Conservative Party said that Mr Ashcroft had also stepped down from his post as Belize's Ambassador to the United Nations in preparation for taking his place in the Lords.

'Moral bankruptcy'

The Tory leader in the Lords, Lord Strathclyde, said the decision to grant Mr Ashcroft a peerage had been made "for a number of reasons".

He said that in addition to his party donations and role within the Tories, Mr Ashcroft was also "an international businessman, a substantial employer in this country and he gives to charity".

Lord Strathclyde said Labour was attacking the decision in an attempt to divert attention from Prime Minister Tony Blair's "stuffing" of the Lords with his own supporters.

But there was further criticism from within the Tory party, with John Strafford, of the Campaign for Conservative Democracy, saying Mr Ashcroft should resign as Tory treasurer when he becomes a peer to be replaced by an elected treasurer.

And former Tory MP Sir Anthony Grant said: "This is a mistake. It looks very bad.

"I think we want to detach ourselves from this notion that people only have to give money and then they can waltz into what is, after all, part of the legislature."

When asked why Mr Blair did not veto Mr Ashcroft, the prime minister's official spokesman said: "The prime minister is not the scrutinising authority in this area."

In 1999 Mr Ashcroft was involved in a bitter libel battle with The Times newspaper and a political row centred around his Tory party donations.

Hereditaries return

Mr Ashcroft's name was on a list of 33 working peers - 20 Labour, four Conservative and nine Liberal Democrats published on Friday.

Their arrival will bring the number of Labour peers up to 202, alongside 236 Conservatives, 63 Liberal Democrats, 161 crossbenchers and 26 Bishops and Archbishops.

Former Olympic gold medallist and now private secretary to William Hague Sebestian Coe was also among those Tories given life peerages.

Among the Labour life peers are five former hereditaries who lost their right to sit in the Lords last November.

The "re-treads" are Baron Acton, Baron Berkeley, Viscount Chandos, Baron Grenfell and Baron Ponsonby.

Other Labour peers also include television executive Alexander Bernstein, chairman of the Bar Council Daniel Brennan, and Matthew Evans, managing director of publishers Faber and Faber .

Among the nine Liberal Democrats are another two former hereditaries, the Earl of Mar and Kellie and Baron Redesdale.