Tony Blair was warned by a member of Labour's ruling national executive he would face a walkout protest if he goes ahead with plans to invite Iyad Allawi, the leader of the iterim Iraqi government, to the Labour Party conference.
Mark Seddon said a number of members of the NEC would walk out in protest if Mr Allawi was invited on to platform at the party conference. The last high-profile walkout occurred when the late Eric Heffer stormed out in protest at Neil Kinnock's attack on Militant.
"I am going to kick up a fuss about this at the next NEC," said Mr Seddon. "A lot of us said at our last meeting we wanted John Kerry to win the presidential election. We should be inviting the Democrats to our conference, not Allawi. There will be a walkout if it goes ahead."
Activists from Labour Against the War have circulated a protest e-mail calling for Mr Blair to be lobbied by Labour members to withdraw the invitation.
Party officials said no official invitation had been issued, but they confirmed that Mr Blair wants Mr Allawi to attend the conference.
The e-mail said: "Iyad Allawi is well known for his former connections to the CIA and MI6. He was a member of Saddam's Baath party." It repeated claims, which Mr Allawi has strongly denied, that he executed six suspected insurgents at a Baghdad police station.
Mr Seddon also protested at the treatment of British journalists in the Iraqi city of Najaf, including Donald Macintyre of The Independent, who reported yesterday that he was warned by local police that he would be shot if he stayed to report the continuing violence.
Downing Street warned against journalists in Najaf making claims that there was a clampdown on the media. "I think we should not be too hasty to turn this into a debate about free speech," said a Number 10 spokesman. "There is quite a lively media in Iraq for the first time in years.
"I think decisions about the presence of the media in Najaf is one for the Iraqi authorities. We are sure that any action taken by them is consistent with the security situation.
"Nobody can be complacent about the situation in Iraq. The Foreign Office travel advice advises against all but the most essential travel to Iraq."
Mr Seddon, former editor of Tribune, said: "The British Government should be encouraging journalists to report the truth in Iraq. It is a complete abrogation of their responsibility to say that."
Meanwhile, Sir Jeremy Greenstock, the former UK envoy to Iraq, said on BBC radio that Mr Blair had 18 months to show that Iraq was a success. He said: "If Iraq in 2006 looks very little better than under Saddam, then the whole thing was a waste of lives, money and effort."
He also claimed that al-Jazeera, the Arab television company, had come close to breaking the law when he was in Iraq by colluding with terrorists. He said the broadcaster's crews sometimes turned up at the scene of bombings before the bombings took place.