Nestle UK said on Wednesday that, in response to consumer concerns, it would either replace GM ingredients or clearly label them where a substitute could not be found.

The move came shortly after similar announcements from Tesco, Birds' Eye Walls and Van Den Burgh foods, which makes the Beanfeast soya ready-meals.

Nicola Carslaw: "The Government says public concern has been whipped up by scaremongering"

Birds Eye said the move was in response to consumers' concerns about the use of GM ingredients, and that it still supported the technology.

Tesco also said the move had been prompted by consumer concerns, citing a survey which said one in four shoppers wanted GM material removed from its shelves.

Environmental charity Greenpeace welcomed the new bans, saying the government is becoming increasingly isolated over GM foods.

Policy defended

A spokesman said: "The government is now so far out on a limb it's unbelievable and I don't think it's sustainable any longer."

Response "is to consumer concerns, not safety"

But in the House of Commons on Wednesday, Prime Minister Tony Blair defended government policy.

Responding to a claim by Tory leader William Hague that there was "mounting public anxiety on the subject", he said the debate was becoming increasingly hysterical.

He said the decision by Tesco to withdraw products containing GM foods had been a "commercial decision" and had nothing to do with safety.

There would be no crops or foods available that had not been "rigorously tested", he said.

And he called for the argument to be conducted "on science, not scares".

Tesco is the last major store to ban own-brand GM foods

Cabinet Office Minister Dr Jack Cunningham echoed Mr Blair's stance in a later meeting with a committee of MPs.

He said labelling of GM foods had been introduced so people could make a choice.

But he said the retailers were making "commercial decisions" on whether or not to sell GM products, based solely on consumer attitudes.