He said that at the moment, the "jury was out"on GM foods.

But he said he believed to impose a ban on them now would be a mistake.

Speaking on the BBC's Breakfast With Frost programme on Sunday, Mr Blair said: "This is an entriely new science.

"Genetic modification has many different areas, for example in medicine, and Britain is at the leading edge of this new technology

Tony Blair: "Let us proceed according to genuine scientific evidence"

"I don't know, but people tell me, it could indeed by the leading science of the 21st century.

"All I say to people is: 'Just keep an open mind and let us proceed according to genuine scientific evidence.'

Mr Blair said he would not want to suddenly ban GM foods, to find in 15 or 20 years that it had been the wrong decision.

The debate on GM crops looks set to run and run

He pointed out that trials on GM crops were proceeding with a "tighter regulatory framework" than virtually any other country, and any other area.

And he said the Labour Government had not licensed a single GM food since it came to power in the 1997 General Election.

A report in the Independent on Sunday said that Cherie Blair was worried about the safety of GM foods, according to Prince Charles.

But when Sir David Frost referred to the report, Mr Blair laughed and said: "I think if I start discussing what Cherie and I talk to each other about at breakfast I'm going to get into a lot of trouble."

'Frankenstein foods'

However he did say he understood the worries of those opposed to GM foods.

But he said there had been a number of reports on the subject, including those from the House of Commons and House of Lords Select Committees, which said there were potential benefits, as well as a potential "downside".

He said: "Let's carry on investigating and making sure we're dealing with this on a sound basis."

"We have to proceed according to basic evidence, and not simply say 'Well, because people talk about Frankenstein foods we chuck the whole thing out of the window'."

Mr Blair also said he welcomed Prince Charles' contribution to the debate on GM foods.

Prince Charles spoke of strong fears about the safety of GM foods in an article in the Daily Mail newspaper last week.