The Conservatives were accused by the French government tonight of "castrating" Britain's position within the EU by adopting an "autistic" approach that would take Britain off the radar.

Speaking to the Guardian, Pierre Lellouche, France's Europe minister, described as "pathetic" the Tories' EU plans announced today, warning they would not succeed "for a minute".

Giving vent to frustration across the EU, which has so far only been expressed in private, Lellouche – who said he was reflecting Nicolas Sarkozy's "sadness and regret" – accused William Hague, the shadow foreign secretary, of a "bizarre autism" in their discussions.

He said: "They have one line and they just repeat one line. It is a very bizarre sense of autism."

Lellouche, one of the most Anglophile members of Sarkozy's government, made his remarkable intervention after David Cameron outlined a fresh Tory approach to the EU in the wake of the full ratification of the Lisbon treaty.

A future Conservative government would seek to strengthen British sovereignty and repatriate a series of powers over social and employment legislation, the Tory leader said.

Cameron said he was not seeking an immediate "bust-up" with the EU, and would allow the repatriation of powers negotiations to last as long as five years.

But that position was not enough for the Tory MEP Daniel Hannan, who quit his role as the party's legal affairs spokesman in Europe, saying he intended to fight for referendums to enable Britain to become "self-governing".

France's centre-right government condemned Cameron's plans, saying that they would marginalise Britain within the EU.

Abandoning all diplomatic niceties, Lellouche said: "It's pathetic. It's just very sad to see Britain, so important in Europe, just cutting itself out from the rest and disappearing from the radar map …. This is a culture of opposition … It is the result of a long period of opposition. I know they will come back, but I hope the trip will be short." He said Cameron's approach was in line with the Tories' decision to abandon the main centre-right EPP grouping in the European parliament, of which Sarkozy's UMP party is a member.

"They are doing what they have done in the European parliament. They have essentially castrated your UK influence in the European parliament," he said.

Lellouche said he has told Hague personally that his position was a "waste of time for all of us".

"I have told William Hague: go away for two to three years, in your political economic situation you're going to be all by your self and you'll come back. Go ahead and do it. That is my message to them … You want to be marginalised? Well, you go for it. But it's a waste of time for all of us," the French minister said.

Lellouche made clear the Tories had no hope of securing support for their plans. "It's not going to happen for a minute. Nobody is going to indulge in rewriting [treaties for] many, many years. Nobody is going to play with the institutions again. It's going to be take it or leave it and they should be honest and say that," he said. "It is a time of tumultuous waters all around us. Wars, terrorism, proliferation, Afghanistan, energy with Russia, massive immigration, economic crisis. It is time when the destiny of Europe is being defined – whether or not we will exist as a third of the world's GDP capable of fighting it out on climate, on trade, on every … issue on the surface of the Earth.

"We need to be united, otherwise we will be wiped out and marginalised. None of us can do it alone. Whether you're big or small, the lesson is the same. And [Britain's] risk is one of marginalisation. Irrelevance." He explained: "Finally we have institutional package, but it took 15 years of looking at our navel and getting everybody bored to death with sterile debate".

In a sign of France's determination to resist the Tory plans to opt out of key EU legislation, Lellouche warned the French would attempt to reduce Britain's EU budget rebate which will be up for negotiation during the next parliament.

He pointed out that France is a net EU contributor to the tune of €5bn (£4.5bn), unlike Britain which receives a rebate.

"If we get a government that is ferociously anti European that will vote down this kind of legislation then I think the relationship is going to be very difficult. As we enter the next phase one of the issues we have to discuss midterm is of course finances. France is a net contributor to the tune of €5bn a year, of which €1.5bn is the same as British rebate. That should tell you quite a bit huh?" he said.

Cameron will be angered by the attack, and what it implies for Tory relations with the rest of Europe although in the short term he will be more concerned to ensure his strategy of abandoning a referendum on the Lisbon treaty does not provoke cries of betrayal on his backbenches.

Hague reacted to the French criticism by insisting that Lellouche's comments did not represent the true reception of the Tories' plans in Europe.

"That is not how we are seen across Europe," he told BBC2's Newsnight, adding his party had established good relations with Sarkozy's party.

"I don't think you will find that's representative of the reaction in Paris or other European capitals," he added.