France’s EU referendum. The noes go marching on

Six weeks left, and a mountain for the yes campaign to climb

DISBELIEF, denial, panic. Such has been the sequence of official reactions as, one by one, over a dozen opinion polls have suggested that the French will reject the draft European Union constitution in their referendum on May 29th. The polls give the noes an average of 53%.

Officially, the government still expects approval. “I believe that the French will vote yes,” insists Michel Barnier, the foreign minister. Privately, officials are deeply worried. Ministers have been told to get out more. Sympathetic foreigners have been roped in. Joschka Fischer, Germany's foreign minister, turned up this week to say that a no would be “the end of the European Union”. And President Jacques Chirac has joined in, planning a televised chat on April 14th with a carefully chosen group of young people.

Can the yes campaigners turn opinion round? There are three tactical issues. First, how much to use Mr Chirac? Presidential authority can help: Francois Mitterrand's televised debate just ahead of the 1992 vote on the Maastricht treaty - a real debate, with Philippe Seguin, a no campaigner - helped to secure a narrow yes. Mr Chirac is good at sweeping appeals to history. Yet he could also provoke a protest vote. Confidence in him has slid from 41% in January to 36% in April, according to TNS-Sofres, a pollster. Many left-leaning voters are reluctant to back the president again - as they had to in May 2002, when the far-right Jean-Marie Le Pen faced Mr Chirac in the presidential run-off.

The second question is how far to dramatise the vote. So far, the left - officially in favour, but bitterly divided - has been keener on this than the right. Valery Giscard d'Estaing, a former president who chaired the convention that drafted the constitution, talks of an “open crisis” if the French say no. But the government is more guarded. Mr Barnier talks only of Europe “stalling”; Nicolas Sarkozy, head of the ruling UMP party, says it would “not be a catastrophe”. Perhaps it is simply too soon to inject a sense of urgency. But perhaps, too, in contrast to the Maastricht vote, which led to the euro, it is hard to say what is at stake in the EU constitution.

The third problem is how to take on the fragmented no campaign. Given that leaders of both mainstream left and right advocate a yes, the potency of the no side seems surprising. Its force comes from its combination of disgruntled political fringes - assorted unionists, revolutionary communists and Trotskyists, plus right-wing nationalists behind Philippe de Villiers and Mr Le Pen - with rejectionists from the Socialist Party, led by Laurent Fabius, the party's deputy leader.

For Francois Hollande, the Socialist leader, the difficulty is especially acute. If he lambasts left-leaning no supporters, he will alienate half his potential support should he run for president in 2007. Yet the temptation is strong. As the heat has risen, so have tempers. “If Le Pen isn't making himself heard during this campaign,” declared Mr Hollande, to the fury of his rejectionist colleagues, “it's because others are doing the job in his place.”

Underlying the campaign are the usual political rivalries, and not just on the left. On a recent TV show, Mr Sarkozy, who is Mr Chirac's chief rival on the right, seemed concerned to promote himself more than the constitution. It took him over 100 minutes to mention Europe - but a lot less to suggest that a rival UMP candidate could challenge the incumbent in 2007.