Prime Minister Tony Blair "I want you to know that you have my profound thanks for all you have done and my belief that, in the future, you will achieve much, much more with us."

Cabinet Office Minister Jack Cunningham "It is a great pity, a great sadness, for me and the government that this year has ended in this tragic, sad and unacceptable way.

"I think that what we've seen here is a minister taking within 24-hours of this matter breaking the right and honourable decision to hand in his resignation to the prime minister.

"That's very different to the way Conservative ministers hung on and refused to go."

Former Mandelson aide, Labour MP Fraser Kemp "I think Peter Mandelson has been a key and, at times, controversial member of the Labour Party and I think what he has done today is put the interests of the Labour Party first."

Shadow Trade and Industry Secretary John Redwood "He has done the right thing in resigning.

"It is a personal tragedy and I take no joy in that but I think it was necessary for the conduct of this government that he went."

Chairman of the Parliamentary Labour Party, Clive Soley "I think people will be reassured that we have managed to demonstrate after a very short time that the standards we have set are high and remain high."

Alan Rusbridger, editor of The Guardian "The Guardian story was published after a two-month investigation. The full story is still to come out, but Mr Mandelson's resignation appears to have been an inevitable result."

Liberal Democrat Leader Paddy Ashdown "According to the letter of the law as we know it, he didn't have to do it, but I think all of us who value probity and the conduct of public duty would like to think that we would have done the same thing.

"I think he is an extremely gifted politician and I have no doubt that having taken this decision swiftly, his career will be far from over, we shall see him again."

Labour Party general secretary Margaret McDonagh "Peter has always put the interests of the Labour Party before his personal interests and once more he has demonstrated his commitment to the success of the party and the government."

Independent MP for Tatton, Martin Bell "Common sense tells you that when you get a loan of this size, you declare it - that's the lesson to all MPs, if in doubt, declare it."

Tory Deputy Leader Peter Lilley

"He [Mr Mandelson] endeavoured to hang on. He went round all the TV studios declaring he had done nothing wrong,"

Liberal Democrats Treasury spokesman Malcolm Bruce

"There is a stark contrast between the swift and honourable resignation of Peter Mandelson and the belated and grudging resignation of Geoffrey Robinson."

Shadow Chief Secretary to the Treasury David Heathcoat-Amory