The BBC's environment correspondent Margaret Gilmore says the government is convinced GM food is safe

The campaign comes amid growing concern at the environmental effects of growing GM crops and fears that they could pollute ordinary crops nearby.

Eighteen of the UK's most respected restaurants, including London's Savoy and the River Cafe, are involved.

Eminent chefs Antonio Carluccio, from the Neal Street Restaurant, and Philip Howard, from The Square restaurant, will unveil a new "Avoiding GM Foods" logo.

The logo is to assure that meals in their restaurants are free of GM foods.

'GM food is safe'

The government says GM foods already on the market, all of which are grown abroad, are safe.

The government has yet to give permission to grow GM food in the UK

But it has ordered more research into the environmental effects before allowing GM crops to be grown commercially in the UK.

The only GM crops being grown in the UK are a 25 acre field of genetically modified oilseed rape in Wiltshire.

On Tuesday a High Court judge refused to impose a ban on protesters who uprooted GM crops.

'Protesters tore up crops'

The application for a permanent ban was made by Monsanto after six members of the environmental concern group GenetiX Snowball tore up experimental crops at a farm in Oxfordshire last year.

But Mr Justice Klevan said he could not grant an injunction, because the protesters could have a defence against it.

On Sunday a community picnic in London designed to promote organic food and protest at GM food was cancelled after the organisers were overwhelmed with people wanting to attend.

Sainsbury's is phasing out the use of GM food

Organisers of the event on Primrose Hill, north London, said advance publicity - which included mention of singer George Michael's plans to attend - led to the picnic becoming "too big".

One of the organisers, Birgit Cunningham, 33, said: "The Royal Parks Agency said there was no way in the time left that we could organise enough security."

She said the picnic was originally planned for 800 but about 10 times that many expressed interest.

The plan now is for the picnic to be rearranged at a larger park later this year.