Tony Blair today ruled out making an immediate decision on whether Britain should proceed with its planned referendum on the European constitution after the restive French public decisively rejected the treaty last night.

Mr Blair, speaking at a press conference in San Gimignano, Tuscany, where he is on holiday, called for "time for reflection" as the political fallout of the 'non' vote becomes clear.

He said: "Underneath all of this there is a more profound question which is about the future of Europe and, in particular, the European economy."

French voters delivered a potentially fatal blow to the constitution and their own political establishment last night rejecting the treaty by a ten-point margin, humiliating President Chirac and plunging the EU into the deepest crisis of its 50-year history.

Mr Blair said that he remained optimistic that the Dutch would vote in favour of the treaty when they go to the polls on Wednesday.

But even a surprise lifeline from the Netherlands is unlikely to save the constitution, with many commentators saying that the scale of the French rejection - 54.87 per cent voted against - has effectively left it dead and buried.

Only nine of the EU's 25 members have so far ratified the treaty, which must be unanimously adopted among all member states. A scheduled EU summit in Brussels on June 16 will now become a crisis meeting to decide a way forward.

Mr Blair said that Europe must now address a "profound question" about its future, in particular the pathway towards economic reform. These are likely to become profound issues for debate when Britain assumes presidency of the EU on July 1.

Mr Blair said: "What is important now is having a time for reflection with the Dutch referendum in a couple of days’ time and the European council in the middle of June where the leaders will discuss the implications of the votes that have taken place.

"But I think that underneath all this there is a more profound question, which is about the future of Europe and, in particular, the future of the European economy and how we deal with the modern questions of globalisation and technological change.

"And how we ensure the European economy is strong and is prosperous in the face of those challenges."

Jack Straw, the Foreign Secretary, told the BBC that the Government would make a formal announcement to the Commons on Monday.

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