Will Tony Blair re-enter politics as the EU’s first president? The tantalising idea has been dangled in front of Europe’s leaders by Nicolas Sarkozy. This despite the fact that when Blair addressed Sarkozy’s UMP party in Paris he made clear that if he was French he would be a member of the Socialist party – but on its modernising wing.

Immediately, the ancient mariner of EU politics, Valery Giscard d’Estaing stepped forth to say Blair couldn’t be EU president because Britain is insufficiently European. He was backed by a former right-wing French premier, Edouard Balladur. Events, time and the emergence of other names will decide whether Blair wants to give up an income that is beginning to match that earned by top editors and current affairs presenters and revert to the decent but relatively modest emolument of a top EU official.

But what is the new president of the EU? For a start, he (or she) is not the president of Europe. The job is to preside or chair the European Council – the assembly of nation-states that decides whether to allow proposals from the European Commission to become EU law.

The new post replaces the rotating 6-month presidency. Right now it is held by Slovenia. From July it will be France for six months. And then comes AN Other country. Having a permanent chair of the European Council allows – in theory – some continuity and co-ordination.

Does the new president speak for Europe? Yes and no. The President of the European Commission will still see himself as Number One European. There will also be a new post of High Representative for Foreign Affairs who will be busy scurrying from crisis to crisis speaking for Europe.

And the new president of the European Council will not easily be able to say anything out of line with the policies or views of the heads of the 27 EU member states who appoint him. If he says Europe needs more nuclear power, the Germans will go, well, nuclear as Berlin blocks any reference to nuclear power in EU energy policy announcement. If he says the European Central Bank should be strong and independent and maintain the stability and value of the Euro, Paris will get angry as Mr Sarkozy keeps attacking the ECB and wants to re-politicise monetary policy.

If the new president praises social Europe, Whitehall will shut its doors and start muttering about him as they muttered away about Romano Prodi’s delusions about being a second Jacques Delors.

So the new president will have to be a statesman, a crafty diplomat, a soother of European quarrels, competent at managing the tedious minutiae of EU business, able to speak two or three languages, and a father figure who can make the EU popular again.

In short, rather more qualities are needed than those required to be manager of England, secretary general of the UN, or Archbishop of Canterbury. Will the post make the man or woman who first fills it? Or will the first president be able to define, refine, and make the presidency a post that lives up to the ambitions of countries like France and Britain who insisted it should be created?

The job specification will be written once the post is filled. Some prime ministers are already touting themselves around Europe’s capitals. Mr Sarkozy announcing Tony Blair as his preferred candidate may actually be killing Blair’s chances with such an early embrace as the rest of Europe hate being told who they must choose by one powerful figure.

Yet for all that, Blair remains one of the big European leaders. He speaks French. Americans listen to him. He is still young. The world would respect an EU whose titular head was Tony Blair. Whether he wants to submit himself to the dreary bargaining to get anything done in Brussels is another question. When he and I entered the bunker-like office block housing the European Council in Brussels, Blair groaned and visibly wilted at the hours of numbing talks that lay ahead to move Europe forward. Yet he was better than most at making the EU do things it needed to do. Will he want five years of hard EU grind again? Having created the post with its challenging title – ‘President of Europe’ – the task of finding someone to do the job is far from easy.