There’s no accounting for politics. It can make even the best laid plans go awry. The Berlin-driven fiscal discipline treaty was completed on Monday. A delighted Angela Merkel, German Chancellor, praised the “very successful outcome” of the summit. But  the very same document looks set to become a football in France’s April presidential elections.  Socialist candidate Francois Hollande, leading in the polls, appears intent on making the presidential election a de facto referendum on the treaty.

By the time French elections come about – the first round is on 22 April – the treaty will have been signed by President Nicolas Sarkozy but not ratified by parliament.

Hollande has promised to renegotiate the treaty if he wins. “If he is elected, he will ask for the renegotiation of this treaty to complete it and rebalance it … to get Europe out of its spiral of austerity,” his campaign manager Pierre Moscovici said Tuesday. Indeed, Hollande, who would be the first Socialist president in 17 years, has said his first trip abroad if he wins would be to Berlin.

He wants more focus on growth and has spoken out in favour of a greater role for the European Central Bank and the creation of eurobonds.  Good – he is in campaign mode. He can say what he likes without being constrained by the political realities of a) office or b) the wishes of other member states.

Still, the latest opinion poll gives him 31 percent support. Sarkozy – who has yet to declare his candidacy – has 24.5 percent.   Sarkozy’s camp are saying it is not possible to renegotiate after the president’s signature. Certainly it would be difficult and it would depend on what other member states  (many of whom – Italy, Spain, Lisbon, Athens, Dublin – need Berlin) say.

But the Socialists have had a similar such experience in the past. In 1997 they kicked up a fuss about the stability pact – the rules underpinning the euro – and threatened to renegotiate it.  Eventually they won some small concessions including having the pact named the stability and growth pact.

(Technically, France does not have to ratify the fiscal compact for it to come into force elsewhere. It goes into effect once 12 of the 17 eurozone countries have ratified it. Politically, of course, is another matter entirely. France refusing to ratify the treaty would poison relations between Paris and Berlin. Hollow out the point of the treaty as France has a long record of high public spending. And cause more uncertainty in the markets.)

Merkel has been pushing the treaty saying that a fiscal discipline pact will calm markets – not to say her backbenchers – but there are real fears that its belt-tightening focus may compound Europe’s economic misery.  And French people are already jittery. Unemployment is at its highest rate in 12 years. Tough austerity measures have been taken. More will come. Hollande’s anti-treaty rhetoric may well strike a scapegoat chord.

In that sense, Merkel’s remarkable offer to make campaign appearances with Sarkozy is very tricky. Sarkozy, assuming he runs, will have to judge whether Merkel is good for his image or whether the German chancellor becomes associated in French voters’ minds with austerity and job loss.