Mr Wilkie said the apology came as both Mr Abbott and Prime Minister Julia Gillard began to court his support as a key player in the shape of the next parliament.

The former intelligence analyst was pursued by the Howard government in 2003 after his decision to quit its Office of National Assessments and speak out as a whistleblower against the war.

Prime minister John Howard claimed at the time that Mr Wilkie was ''guilty of distortion, exaggeration and misrepresentation'' in his attacks on the government's use of intelligence.

Liberal Senator David Johnston went further, describing Mr Wilkie as ''unstable and flaky'', earning a rebuke from Mr Howard, who also expressed regret for a suggestion out of his office that Mr Wilkie was ''unbalanced''. Seven years later, the one-time army lieutenant-colonel is beginning what he pledges will be ''transparent'' talks with both Mr Abbott and Ms Gillard, though Mr Wilkie is still stopping short of claiming victory in the Hobart seat of Denison.

Mr Wilkie said that in a telephone conversation yesterday Mr Abbott noted the way he had been treated over the war by the Howard government. ''And he said that although he is still a strong supporter of the Iraq War, he did apologise for the way I was treated … Members of the Howard government vilified me publicly, both in the House of Representatives and the Senate, and he was trying to build a bridge with me.

''I said thank you. That's over. The way I was treated by the Coalition and the Howard government, that is history.''

A spokeswoman for Mr Abbott said she would not comment on what was a private conversation.

Mr Wilkie insisted he had a ''blank sheet of paper'' over his choice of whether to support Labor, the Coalition or to remain unaligned.

Ms Gillard personally arranged, through Mr Wilkie's wife, Kate Burton, to meet him on Saturday in Melbourne. Mr Abbott will see him in Canberra on Monday.