Ireland must hold a second referendum on the Lisbon treaty, Nicolas Sarkozy told colleagues yesterday in the clearest sign of a European Union plan to try to save the document ratified by 21 other countries.

A second vote would have to take place in an attempt to reverse Ireland's rejection of the treaty last month by a margin of 53.4 per cent to 46.6 per cent, the French President told MPs from his party at a private meeting.

Mr Sarkozy, who is acting as chairman of the EU while France holds its presidency for six months, has denied in public that there is a secret plan to force a second vote and has said that the solution must be proposed by the Irish Government at the next EU summit in October. “The Irish will have to vote again,” he was reported to have told a meeting in his office — words that are likely to inflame public opinion in Ireland, which Mr Sarkozy will visit on Monday.

His trip is billed as a listening exercise, but Irish voters may now wonder whether Mr Sarkozy and other EU leaders have already made up their minds. Details emerged in Paris of a plan to stage a rerun of the vote backed by guarantees that Ireland will keep its EU commissioner as well as its military neutrality, its veto over tax policy and its right to set its abortion laws.

Pressure on Ireland has been increased by the continuing pace of ratification by other parliaments. Britain passed the document the week after the Irish “no” vote, followed by Cyprus, Belgium and the Netherlands.

The treaty, which was intended to streamline decision-making in an enlarged EU, cannot be implemented until it is ratified by all member states. It has yet to be passed by the parliaments of the Czech Republic, Italy, Spain and Sweden, and is awaiting formal presidential signature in Germany and Poland.

Senior EU politicians have called for the Irish to vote again in the spring because they want to conduct next June's European Parliament elections under the more streamlined rules.

An official in Paris confirmed that Mr Sarkozy made the remark, while the French President's office declined to comment. The reported remarks were attacked by Declan Ganley, of the Libertas group, one of the most prominent anti-treaty campaigners. “This typifies the anti-democratic nature of what's going on in Brussels,” he told RTE radio.

Mr Sarkozy's office said that he would not present a plan to the Taoiseach, Brian Cowen. “The President is coming to listen to the Irish, to listen to what Brian Cowen tells him. He is not coming to make proposals,” one adviser to Mr Sarkozy said.

Sinn Fein described Mr Sarkozy's comment as “deeply insulting to the Irish people”. Aengus Ó Snodaigh, a spokesman, said: “In the month since the Irish people voted overwhelmingly to reject the Lisbon treaty, we have listened to a succession of EU leaders lining up to try and bully and coerce us into doing what they want.”

William Hague, the British Shadow Foreign Secretary, said: “It would be extraordinary if Irish voters were made to vote twice on this EU treaty before British voters got to vote once. The EU needs to remember that asking people to vote again and again until you get the answer you want doesn't look very democratic.”

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