Jack Straw and Geoff Hoon are to be the first members of Tony Blair's Cabinet to give evidence to the Iraq Inquiry.
Mr Hoon, who was Defence Secretary at the time of the invasion in 2003, will appear next week for two three-hour sessions on Tuesday January 19.
He will then be followed on Thursday January 21 by Mr Straw - the current Justice Secretary who was Foreign Secretary in 2003 - who will give evidence in a single three-hour session.
Mr Hoon was one of the main figures behind last week's abortive coup attempt to force out Gordon Brown.
There has been speculation that he will now use his appearance before the inquiry to try to further damage the Prime Minister.
The Sunday Times reported at the weekend that leaked letters showed that Mr Brown, when he was Chancellor, blocked the release of funds for additional helicopters for use in Iraq and Afghanistan.
The paper said Mr Hoon refused to comment on suggestions that he had even appealed to Mr Blair to intervene.
After Mr Blair, Mr Straw was the minister most closely associated with the military action against Iraq.
As Foreign Secretary, he was a key player in the diplomatic efforts to try to resolve the crisis over Saddam Hussein's supposed weapons of mass destruction through the United Nations Security Council. He is likely to face questions on whether he had any misgivings over the use of military force to topple the Iraqi dictator.
Other witnesses next week include Jonathan Powell, who was Mr Blair's chief of staff at No 10 and one of his closest advisers. He gives evidence on Monday.
