A Birmingham Labour MP remained defiant last night as the threat of disciplinary action by her own party hung over her.
Gisela Stuart has angered the party hierarchy over her backing for a campaign to force a referendum on the EU Reform Treaty.
The Edgbaston MP said Chief Whip Geoff Hoon was "not happy" when she was invited to a meeting with him over the issue last Friday.
She is one of three MPs who could face disciplinary action at the weekly meeting of the Parliamentary Labour Party tonight over their links with the I Want a Referendum campaign.
Senior Tory Andrew Mitchell criticised Labour's "bullying" tactics which are aimed at ensuring all MPs are behind proposals to sign up to the Lisbon Treaty.
Ms Stuart, a former Europe Minister, was said to be one of three former ministers who have been threatened with having the party whip withdrawn following frosty encounters with Mr Hoon. The others are Frank Field and Kate Hoey.
However, Ms Stuart denied that a threat to remove the whip had been made.
Former Welfare Reform Minister Mr Field said he was "shouted at" by Mr Hoon because of his involvement with the I Want a Referendum group, which is organising referendums in marginal seats on whether to sign up to the Lisbon Treaty.
An unofficial ballot will be held in Jacqui Smith's Redditch constituency, which the Home Secretary holds with a majority of 2,716.
Mr Field said Mr Hoon had scored a "big own goal" because his threats had given the campaign a higher profile.
Critics of the Lisbon Treaty claim it is a "rebadged" version of the scrapped EU constitution and should be ratified only after a referendum.
All three main parties promised a referendum on the constitution in their 2005 election manifestos.
Referring to the party meeting tonight, Ms Stuart said: "There is a meeting which I am going to and I will see what they have to say.
"The Chief Whip has not suggested to me that they are going to withdraw the whip from me. I do not want to go there because that is not the issue."
She said she supported a Labour Government, and the Labour "policy" that was included in the manifesto to have a referendum on the EU constitution.
"I know Geoff was not too happy about this but that is what Chief Whips do. I saw him on Friday afternoon and he was not very happy, but that is his job," she added.
"I am saying that I would like a referendum in line with the party manifesto. I am not at odds with my party, I am actually in line with the Labour Party manifesto and a party commitment."
Mr Field said: "I'm surprised at the ineptness of the leadership in trying to expel people from the Parliamentary Labour Party for keeping their election promises.
"You would think they would be taken off to the lunatic asylum."
Mr Field did not know what form the proceedings will take when the "lord high executioner arrives" at the PLP meeting in Westminster tonight, but said he would push for a vote on his future.
Mr Mitchell (Sutton Coldfield), the party's shadow Minister for the West Midlands, said: "This is yet more evidence of the bullying approach from the Labour whips office."
The Labour Party was unavailable for comment last night.