1.  When Lord Ashcroft was made a Conservative Life Peer he gave the following assurance;

Mr. Ashcroft has told The Times that he recognises the public concern about foreign funding of British politics, and that he intends to reorganise his affairs in order to return to live in Britain. The Times applauds this.
Statement from The Times, Reproduced by PA, 9 December 1999

In order to meet the requirements for a Working Peer, Mr. Michael Ashcroft has given his clear and unequivocal assurance that he will take up permanent residence in the United Kingdom again before the end of the calendar year. He would be introduced into the House of Lords only after taking up that residence. These undertakings have been endorsed by the Leader of the Conservative Party and conveyed to the Prime Minister - and to the Political Honours Scrutiny Committee
Press Release announcing the creation of Working Peers, 31 March 2000
http://www.number10.gov.uk/output/Page2796.asp

At the time, William Hague said the decision will 'cost him tens of millions a year':
 
After Lord Ashcroft's nomination for a peerage was rejected in 1999 - in part because of his status as a tax exile - Mr. Hague wrote to Downing Street demanding a change of heart on the grounds that the businessman intended to become resident in Britain "in order properly to fulfill his responsibilities in the House of Lords". Mr. Hague added: "This decision will cost him (and benefit the Treasury) tens of millions a year in tax, yet he considers it worthwhile."
The Guardian, 9 November 2007

2. David Cameron has specifically said that he has sought and received satisfactory assurances that Lord Ashcroft is resident in the UK and pays taxes in the UK;
 
'What I think its right for me to do is those things that are within my control. This is something I can sort out and I have set out how I propose to sort it out today and I think it's a useful step forward. I've answered the question about Lord Ashcroft many times before, he gave assurances at the time he was made a peer and I've sought reassurance that those assurances hold and have been given them and I'm happy to leave it at that.'
David Cameron, Press Conference, 5 February 2008
 

DC: I am satisfied that the undertakings he gave are being met and I've had reassurances on that. But I would like to put it in context...

AM: Being met, but haven't been met?

DC:      You know ... no, in terms of the reassurances that he is resident in the UK and pays taxes in the UK, but the point I would like to make, if you look at the last year, actually Mittal and David Sainsbury have given more money to the Labour Party than Lord Ashcroft has given to the Conservative Party. So, I think people get his importance out of all relative significance. 
David Cameron and Andrew Marr, Sunday AM, 2 December 2007

Shadow Leader of the House of Commons, Theresa May, confirmed David Cameron's comments and claimed it was "a pretty clear statement".

TM:      Well this question was asked to David Cameron this morning at the press conference that took place at the launch. He made clear that at the time that Lord Ashcroft was given...er put forward for a peerage, he gave assurances about his status, David Cameron has sought reassurance from him on that point since and he has been given that reassurance.

AA:      It's not the most transparent of statements?

TM:      I think it's a pretty clear statement.
Theresa May, Radio 5, 5 February 2008

3.  However, Lord Strathclyde, Conservative Leader of the House of Lords, has implied today that he does not know if the assurances given have in fact been met;
 
Lord Strathclyde told The Mail on Sunday: 'Michael Ashcroft gave several assurances regarding his tax status, when he accepted his peerage. If legislation is brought forward to ensure that UK legislators [MPs and peers] pay taxes in this country, then my party will support it. And if it becomes law then everyone, including Lord Ashcroft, will have to comply with it and declare whether they are a UK taxpayer. If he is not a UK taxpayer, then he, and every other peers in that position, would have to give up their seats in the Lords.'
Mail on Sunday, 10 February 2008
 
4.  And Shadow Secretary of State for Culture Jeremy Hunt now claims that "Lord Ashcroft's residency status is a matter for him" and does not matter because his donations have been through British companies.

AB: The challenge there from Geoff Hoon basically saying David Cameron's talking about transparency and yet we really don't know if Lord Ashcroft, who's given millions and millions of pounds either directly or through his companies is a foreign resident or not?

JH: Well In think Lord Ashcroft's residency status is a matter for him. What matters is whether his donations to the Conservative party are legal and permissible and they all are legal and they all are permissible.

AB: Well you say that, we don't know that for definite do we? We can't find him on the electoral roll anywhere?

JH: Well anything that he's given has been given through companies that are British companies and are entitled to make those donations and he has been absolutely scrupulous in making sure that his donations are completely above board.
Jeremy Hunt and Adam Boulton, Sky News, 10 February 2008