The prime minister has warned against the creation of "two rival centres of power" following divisions over the war in Iraq.

Conceding that the "world appeared to split into two parts" over the conflict, Tony Blair called for a considered and honest debate about the future.

His comments followed a warning that President Chirac's vision of two competing power blocs would be "destabilising".

Following rifts between Europe and America the prime minister said the two continents needed to "construct a strategic, genuine partnership".

"The fact is that in terms of our economy, in terms of the way people live, in terms of our values, the values of Europe and America are the same," said Blair.

"I think if you ended up with two rival centres of power you would find a very difficult situation."

A transatlantic partnership would be essential to avoid a return to the era of the cold war, the prime minister told reporters.

"My fear is that if we don't deal with the world on the basis of a partnership between Europe and America then we will in a sense put back into the world the divisions that we wanted to get rid of when the cold war finished," he said. "I think that would just be a disaster for the world."

The premier, who risked Britain's position in Europe by standing side by side with the US, called for an "honest discussion" about the future shape of geo-politics.

"That needn't be and shouldn't be acrimonious or bitter or personalised. But it should be about what is an agenda that could form a partnership for the modern world."

Blair added that the key issues of concern were terrorism, weapons of mass destruction, the Middle East peace process, the environment, global poverty and free trade.

And in an interview with the Financial Times, the prime minister warned that President Chirac's vision for Europe is "dangerous and destabilising".

But he distanced himself from Washington hawks who suggest that the French government should be "punished" for its failure to back America in the build up to war.

"I am not really interested in talk about punishing countries, but I think there is an issue that we have to resolve here between America and Europe and within Europe about Europe's attitude to the transatlantic alliance," said Blair.

"I don't want Europe setting itself up in opposition to America...I think it will be dangerous and destabilising,"

He warned that France's long term vision of a united Europe acting as a counterweight to the US would "very quickly develop into rival centres of power".

Such a development would mean "reawakening some of the problems that we had in the cold war with countries playing different centres of powers off each other".

His comments came as a MORI poll for the FT found that 55 per cent of Britons regard France as the UK's least reliable ally, while 73 per cent feel that the US is the country's most reliable.