Although Britain is not yet part of the "first wave to join Europe's single currency, London will be at the centre of the euro", he said in an article in the Wall Street Journal.

Britain has to learn that Europe can only get more important for it, blair said, adding that more than 50 per cent of the country's trade is with the euro zone and so steps to enhance it should be taken.

As to why Britain has delayed its joining the euro bloc, Blair said," it would not have been in Britain's national economic interest to do so at this stage."

The British and continental economic cycles are still out of step. Interest rates in Britain are still at six per cent, double those of continental europe at three per cent., he said, adding that over a period of several decades, Britain's economy had been subject to far greater fluctuations in the economic cycle, the boom and bust pattern, than is the case of our main European partners.

Britain will shortly publish an outline national changeover plan setting out the practical steps it would need to take if it decides to join the euro, he said.

"But Britain needs a period of settled and sustainable convergence before we are in a position to take a decision. Other countries in Europe have already gone through this phase," Blair added.

"There is no constitutional bar to Britain joining the single currency. If the euro works and the economic benefits are clear and unambiguous, we would recommend entry, with the British people having the final say in a referendum," Blair said.

The US, meanwhile, is in the throes of a debate over whether the euro will eventually emerge as a rival to the dollar and thus weaken the United States.

While some hold that the US will benefit by the expansion of Europe's economy as a result of the euro, others are not so sure.

What worries many Americans is that the euro will lead to the creation of not only an economic bloc that will rival the US. But that Europe will also challenge US supremacy as the world's only superpower through the political integration of Europe following economic integration.

"This," said Jeffrey E. Garten, Dean of the Yale School of Management and former Undersecretary of Commerce for International Trade, "is a transforming event. Financial clout will translate into political confidence. Europe is going to be much more of a power to be rckoned with even in nonmonetary areas if it has monetry power."