The Conservative leadership came under double attack today when two frontbench Eurosceptics resigned and a French minister accused the party of political “autism”.

The furore was caused when David Cameron abandoned a referendum on the Treaty of Lisbon last night, as the constitutional changes it enshrines had been ratified across Europe. As a sop, he promised to do more as Prime Minister to help repatriate powers to Britain from Brussels.

This was not enough for Roger Helmer, the Conservative employment spokesman in the European Parliament, who quit this morning accusing the Tory leader of offering nothing more than cosmetic promises. Daniel Hannan, the party’s legal spokesman in Europe, also quit, saying that the voters had not been given their say.

Meanwhile Pierre Lellouche, the French Minister for Europe, threatened to upset Mr Cameron’s delicate balancing act further by accusing him of “castrating” British influence by pandering to the Eurosceptic wing of his party.

“It’s just very sad to see Britain, so important in Europe, cutting itself out from the rest and disappearing from the radar map,” Mr Lellouche told The Guardian.

William Hague, the Shadow Foreign Secretary, dismissed the claim by Mr Lellouche that he was reflecting mainstream opinion in France and the views of President Sarkozy.

“We have had a bit of an emotional outburst from one of the French ministers, but I don’t think we should take that as a sign of how things will be in the future,” he told Sky News. “I think more senior members of the French Government would take a more careful approach. We take that in our stride.”

Mr Hague may have been stung that some of Mr Lellouche’s criticism had singled him out. The French minister accused him of a “very bizarre sense of autism” for continuing with his Eurosceptic line.

Mr Lellouche, a noted Anglophile, challenged Mr Hague to see what would happen if the Tories persisted in their stance.

“I have told William Hague: go away for two to three years, in your political economic situation you’re going to be all by yourself and you’ll come back. Go ahead and do it, that’s my message to him. You want to be marginalised? Well, you go for it. But it’s a waste of time for all of us.”

The attack by Mr Lellouche has embarrassed the Sarkozy Government because of its outspoken language. The Élysée Palace declined to comment.

However, the minister, a maverick of the French conservative scene, was expressing in undiplomatic language the known dismay in the French Government and political world over the European policies of Mr Cameron.

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