France on Wednesday branded British government plans to hold an in-out referendum on European Union membership as "dangerous".

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British Prime Minister David Cameron promised in a speech on Wednesday to hold a referendum on Britain's place in the EU if his Conservative party are re-elected to power in 2015.

But in an interview with France Info radio French Foreign Minister Laurent Fabius said a referendum would place Britain in peril.

"It risks being dangerous for Britain itself because Britain outside of Europe, that will be difficult," Fabus said, adding that Britain could not treat Europe as an "a la carte menu".

"We hope Britain can make a positive contribution to Europe. Imagine the EU as a football club. When you join it, you are in. You cannot just decide to go and play rugby," Fabius added.

Cameron said in a long-awaited speech that he wants to renegotiate the terms of Britain's EU membership before putting the new deal to a vote

In extracts from his speech, which were released in advance, the prime minister said Britain as a nation should decide on its future place in Europe.

"It is time for the British people to have their say," he said. "It is time to settle this European question in British politics. I say to the British people: this will be your decision."

As well as signalling that France would oppose Cameron's plans to build a new, exclusively trade-based relationship with the EU, Fabius said withdrawal from the bloc would hit investment in Britain.

"The other day I had a meeting with British businessmen and I told them: Listen, if Britain decides to leave Europe, we will roll out the red carpet for you."

Cameron infuriated French leaders last year by remarking that he would roll out a red carpet for entrepreneurs moving to London to escape France's higher wealth taxes.

The spokeswoman for France's socialist government Najat Vallaud-Belkacem also insisted Britain should remain in the EU.

Being a member of the European Union has a number of obligations," she said.

"The Europe that we believe in is a pact of solidarity and that solidarity applies to all member states."