Suspended Labour MP George Galloway says he has been banned from attending a meeting of his constituency party in Glasgow.
George Galloway: "Further gagging order"
Notice of the move came in a letter from the Labour Party's general secretary, David Triesman, received by the Glasgow Kelvin constituency secretary on Friday morning.
Mr Galloway was flying from London to attend the evening meeting when it was delivered.
The left-wing MP was suspended after branding Tony Blair a "wolf" and making comments seen as urging Arabs to rise up against the coalition forces at the height of the war in Iraq.
He had also said, in an interview with Abu Dhabi television, that British troops should refuse to follow what he said were illegal orders.
Mr Galloway described Friday's letter as "a further gagging order on free speech in the party".
He is not allowed to represent the party or attend general committee meetings of his constituency party or all member meetings
"On the day when the papers are full of the lies, forgeries and deceptions and dirty tricks employed to fool Britain into war, I was looking forward to explaining for the first time to my own party members the true nature of the campaign against me," he said.
The meeting had been arranged to hear his arguments and discuss the implications of his suspension ahead of the imminent selections for the new constituency of Glasgow central, which Mr Galloway is tipped to win.
The chairman of the constituency Labour party, Mark Craig, said members the meeting would go ahead without Mr Galloway.
He said that when Mr Galloway had been told he had been suspended as an MP but was still a member of the Labour Party and assumed he was banned only from parliamentary meetings.
"Most members I've talked to are disappointed they are not going to have an opportunity to hear George and put questions to him.
"They are also being denied the ability to speak out on this issue," Mr Craig said.
A motion on freedom of speech within the Labour Party would be discussed at the meeting, he added.
A Labour Party spokesman said: "George Galloway is being treated no differently to any member who has been suspended administratively.
"As such, he is not allowed to represent the party or attend general committee meetings of his constituency party or all member meetings. Mr Galloway was informed of this on May 6.
"The party is now looking as quickly as possible into complaints about comments Mr Galloway reportedly made and into the allegation that he acted in a way that is prejudicial or grossly detrimental to the Labour Party's interests."
Later, Mr Galloway insisted to the BBC that everything he had said before and during the war had been vindicated by events.
He accused the prime minister of taking Iraqi schoolchildren hostage for a photo-opportunity in a way that would have made Saddam Hussein blush.