Gordon Brown has written to the Iraq Inquiry stressing that he is happy to appear "at any time", he told the Commons today as pressure mounted on the Prime Minister to give evidence ahead of the general election.
Mr Brown said he had made the offer in a letter to inquiry chairman Sir John Chilcot - which Downing Street later said was a new letter - but would take direction from Sir John about when to appear.
Demands have been growing on the Prime Minister to give evidence ahead of the general election which must be held by June after he was accused of starving the armed forces of essential funds.
Former defence secretary Geoff Hoon told the inquiry that the Treasury, under Mr Brown as chancellor, failed to fund the forces properly in the years before the conflict and then slashed their budget following the invasion.
At Prime Minister's question time, SNP Westminster leader Angus Robertson said: "The Chilcot Inquiry has heard that you were in the Iraq War inner circle and refused key payments for our troops on the front line.
"Will you confirm to the House that there is no impediment for you to seek a time to give evidence to the Chilcot Inquiry before the general election?"
Mr Brown replied: "This is, as I said, a matter for the Chilcot Inquiry.
"I have written to Sir John Chilcot and I have said to him that I am happy to give evidence at any time. That is a matter for the committee to decide, but I will take whatever advice he gives me about when he wishes me to appear.
"I am happy to give evidence about all the issues that he puts forward, and I am happy to satisfy the public of this country about our Government's commitment to the security of this country."
Last week Mr Brown insisted he had "nothing to hide" after Liberal Democrat leader Nick Clegg said the public were entitled to know his role in the Government's "most disastrous decision" before casting their votes on polling day.
Sir John has indicated that hearings will not be held in the run-up to the election to allow the inquiry to remain outside party politics.
Former Number 10 spin chief Alastair Campbell told the inquiry last week that Mr Brown, who was then chancellor, was part of the "inner circle" of ministers and advisers Tony Blair consulted in private on Iraq.
And Mr Hoon said this week that orders for vital new equipment - including additional helicopters which could have been used in the current conflict in Afghanistan - had to be cancelled as a result of the Treasury's cost-cutting measures.
Shadow foreign secretary William Hague said he hoped Mr Brown's letter would lead to the Prime Minister giving evidence to Sir John's panel before voters go to the polls.
"We welcome the fact that the Prime Minister has finally done what we have called for and what the British public expects and made himself available to the Iraq Inquiry at any time," Mr Hague said.
"We hope that this will now pave the way for Sir John Chilcot to call on the Prime Minister to give evidence before the general election.
"It is only right and proper that all those who played a role in taking the country to war give evidence before the general election."
In his letter to Sir John Chilcot, sent yesterday, Mr Brown said: "I am clear that it is a matter for you how you conduct the Inquiry and that it is, and must remain, entirely independent of Government.
"In undertaking this you have rightly chosen the order you wish to receive evidence.
"For my part, I want to make it absolutely clear I am prepared to give evidence whenever you see fit. I remain happy to take your advice on this matter."
A Downing Street spokesman added: "As the Prime Minister has made clear on several occasions, the Government will continue to cooperate fully with the inquiry."
Liberal Democrat leader Nick Clegg said: "Gordon Brown has done little or nothing to change his position.
"He must insist, on behalf of the British people, that he appears at the inquiry before the election.
"Based on his mealy-mouthed comments today, the British people are no nearer to seeing the testimony of the man who signed the cheques for this disastrous war."Reuse content