Brussels delivers blow to EU referendum hopes

Tony Blair's battle to win a referendum on the European constitution suffered a setback yesterday when the European Commission said the document might have to be revised within the next decade.

Tony Blair's battle to win a referendum on the European constitution suffered a setback yesterday when the European Commission said the document might have to be revised within the next decade.

The comments from Jose Manuel Barroso, the EC President, undermine one of Downing Street's central arguments: that the constitution will finalise the relationship between the UK and the EU.

At issue is the question of the voting system in the constitution which is based on the populations of member states. Projections show Turkey will be the EU's most populous county within decades, so giving it greater decision-making weight than Germany, the UK or France.

In the French daily, Le Figaro, Mr Barroso sought to reassure French opinion by trying to separate the constitution from the question of Turkish membership. He said: "If there is a need to change the rules later we will do it. But that is not the issue today." His spokeswoman, Francoise Le Bail, added: "When the time comes to change the constitution we will discuss it but the time has not come."

The EU has agreed to start membership talks with Turkey in October but negotiations will be lengthy and Ankara will not enter the EU before 2015. Any change to the voting system would have to be done before Turkish accession and be agreed by all member states.

Although policy-makers are discussing the possibility of changing the rules informally, no serious work is being done on the issue at present. Such an exercise would, in fact, be to the advantage of the UK since it would reduce its prospects of being outvoted on key issues.

But critics of the constitution will also seize on the comments as an admission that it does not equip the EU with the decision-making machinery it needs for the foreseeable future. France, where the majority of voters oppose Turkish membership, is to vote before the summer in a referendum on the constitution.