A Labour MP has clashed angrily with EU treaty referendum campaigner Derek Scott in a BBC radio interview.
I Want a Referendum was launched by a cross-party group of MPs
Andrew Slaughter accused Mr Scott of fronting a "dishonest" marketing exercise for the Conservative Party.
But Mr Scott - a Labour supporting former adviser to Tony Blair - insisted I Want a Referendum (IWAR) had support from across the political spectrum.
The campaign is holding referendums in Labour and Lib Dem areas - including Mr Slaughter's west London constituency.
The unofficial votes will take place in 10 marginal constituencies, with one in the East Renfrewshire seat held by Europe minister Jim Murphy.
But Mr Slaughter said that rather than being genuine exercises in democracy, the votes were simply aimed at unseating Labour MPs at the next general election.
He also claimed the ballot papers potentially broke electoral and data protection laws and he called on Mr Scott to assure those taking part their details would not be passed on to third parties.
In heated exchanges on BBC Radio 4's Today in Parliament, Mr Scott, who was Mr Blair's economic adviser for six years and is now chair of IWAR's advisory board, insisted the campaign was a genuine cross-party effort.
He said the reason Labour and Lib Dem MPs had been targeted was to remind those parties of their 2005 manifesto commitments to hold a referendum on the EU constitution, which opponents say is essentially the same as the treaty.
He said the campaign was targeting "a mixture of big names, if you like, and less well-known people - and a combination of Labour and Liberal Democrat, as it is those two parties who have basically reneged on the promise they gave before the last election".
But Mr Slaughter said the campaign was a badly organised "shambles" and called on it to reveal the source of its funding, which he claimed amounted to £30,000 per constituency.
He also demanded to know the names of the 30 Labour MPs whom Mr Scott said supported a referendum.
"The question is - who is supporting the campaign to unseat Labour MPs in marginal seats," asked the Labour MP.
"That's the question, Mr Scott, which you need to answer."
Mr Scott replied: "It's a stupid question because it's not at issue. We are not seeking to undermine or deselect Labour MPs or Liberal Democrat MPs. We are seeking to influence the Parliamentary arithmetic.
"Of course we are associated with the Conservative Party because the Conservative Party is the opposition in some of these seats where they, the Conservative Party, have taken a view on the referendum."
Pro-European Tories such as Ken Clarke had not been targeted, Mr Scott said, because Labour and Lib Dem MPs in such constituencies would not be allowed to defy their party line by joining the campaign.
The Conservatives are the only party at Westminster calling for a referendum on the Lisbon Treaty, which MPs are currently debating as part of the ratification process.
But they are unlikely to force Prime Minister Gordon Brown into holding a referendum without the support of Lib Dem and Labour MPs.
The four Labour MPs who have joined IWAR - Frank Field, Kate Hoey, Gisela Stewart, who is married to Mr Scott, and Graham Stringer - have faced a rough ride from party colleagues.
Two of them, Graham Stringer and Gisela Stewart, have quit I Want a Referendum's advisory group after pressure from Labour's chief whip Geoff Hoon, who reportedly threatened to expel them from the Parliamentary Labour Party.
Frank Field and Kate Hoey both said they had not withdrawn from the campaign and would continue to take a full part in it.
Mr Scott said the MPs had been made to feel "uncomfortable" by Labour colleagues over the "incorrect" perception they were trying to unseat Labour MPs.
Mr Slaughter seized on these comments, telling Mr Scott: "So your all-party campaign has been rumbled because when the Labour MPs actually found out what you were doing they withdrew."
Mr Scott hit back: "You may get away with this twisting in the House of Commons but I think people out there actually realise what you are trying to do."
The Labour MP then accused Mr Scott of "pretending to conduct an impartial poll when you are actually supporting a marketing exercise for a political party".
Mr Scott said such a suggestion was "absurd" and the IWAR campaign was supported by "members of all parties and none" and had about 40,000 registered supporters.
But Mr Slaughter said IWAR was "a dishonest exercise from start to finish".
"It's masquerading as something else. It's a marketing exercise for the Conservative Party and its candidates and Mr Scott should be honest enough to admit that," he added.
Hear the exchanges between Derek Scott and Andrew Slaughter on Today in Parliament on BBC Radio 4 at 2330 GMT on Friday, 8 February or download the podcast from the Radio 4 website.