By politics.co.uk staff
Gordon Brown will give evidence to the Iraq inquiry before the general election, it has been confirmed.
Sir John Chilcot announced at the beginning of this morning's evidence sessions he considered it "a matter of fairness" that if the prime minister wanted to appear before polling day he would offer him the option to do so.
Mr Brown has now taken up that offer.
In a letter to Sir John this morning the prime minister wrote: "In my letter I offered to give my evidence at any time. You have proposed a range of dates in the next two months. I will be happy to agree a date that is to the convenience of the inquiry."
The news is a major success for opposition parties who hoped to force Mr Brown to appear before the general election.
At last week's prime minister's questions Liberal Democrat leader Nick Clegg placed huge pressure on Mr Brown which was subsequently echoed by the Conservatives.
Labour strategists have now agreed it would be more damaging for Mr Brown to defer his appearance than get the experience over with.
"From the outset, we have made it clear we wish to stay outside party politics," Sir John explained.
"We wish to collect our evidence in a way in which our evidence will be open about what happened... without the hearings being used as a platform for political advantage by any party.
"It was for this reason... we made a decision we would not call ministers currently serving."
Mr Brown's time as chancellor both before and after the invasion of Iraq meant, as Mr Clegg put it, "not only was he in the meetings but he signed the cheques".
The Iraq war is unlikely to play a significant role in the election but Downing Street will be wary of dredging up old wounds ahead of a public vote.
"It is well known that the prime minister was a key figure in Britain's decision to invade Iraq," Mr Clegg added.
"It is only right that Gordon Brown should explain his role in this disastrous foreign policy failure before asking the British people for their vote."
Shadow foreign secretary William Hague said the prime minister has only himself to blame for the timing of the session.
"It is entirely Gordon Brown's own fault that this is now happening in the run up to the general election," he told the BBC.
"Gordon Brown dragged this out for such a long time.
"It's entirely his only responsibility and he only has himself to blame for that."
International development secretary Douglas Alexander and foreign secretary David Miliband will also appear,it was confirmed today.
The news came just hours after Jack Straw, the first serving Cabinet minister to be quizzed by the inquiry, insisted the decision to go to war had been the hardest of his life.