Senior British government officials are warning that if the French public votes No in its referendum on the European Union constitution, it could undermine Britain's presidency of the EU in the second half of the year.
Political commentators at Westminster have long taken the view that Tony Blair would be privately delighted to see a No vote in France not least because it would rid him of having to try and win a difficult referendum in the UK next year.
But some Downing Street figures watching developments in France say the issue is more complex.
“The idea that we are craving a French No to get us out of having a referendum here is rather simplistic and lazy journalism,” says one senior figure.
“There are good reasons why we would actually be very content with a Yes vote in France and the Netherlands, followed by a drive to get a successful Yes vote in the UK referendum next year.”
Senior figures close to Mr Blair are expressing one big concern about the consequences of a French No. They believe it would signify that the French public has accepted that Europe has become too economically liberal and driven by “Anglo-Saxon” influences.
That, say some British figures, would force President Chirac to take an aggressive stance against Britain on many issues up for debate in the EU. “We would end up with a situation of the French being more French than they normally are,” says one senior official.
Anglo-French tensions could develop on numerous fronts, the official says. In the wake of a No vote, France would be expected to take an even tougher line against the renewal of Britain's EU budget rebate and Britain's continuing opt-out from the 48-hour week.
France might be even more strongly opposed to the liberalisation of services across the EU, a significant objective for the UK.
There could also be tensions over plans, favoured by the UK, for the start of negotiations for Turkish entry to the EU.
Some Foreign Office figures disagree with this pessimistic analysis of the consequences of a French No for Mr Blair as he takes over the rotating six-month presidency of the EU.
“In the wake of a French No, the prime minister would be able to present himself as the conciliator and reconciler, cleaning up the mess that the French have created,” says a senior foreign office figure. “That would be no bad thing.”
Other observers, however, remain convinced that the implications of a French No would be bad for Mr Blair.
“The UK would be in the difficult position of having to defend its positions on issues like the budget rebate while also acting as a conciliator and broker for all 25 member states,” says a London-based European diplomat. “That would make it harder for Blair to end the UK presidency in December with a clear set of achievements in areas such as economic liberalisation under his belt.”
Whatever France decides, Mr Blair is set to press home this week that he is preparing eagerly for the UK referendum. The government bill ratifying the treaty and paving the way for a referendum will be tabled in the Commons tomorrow.
Ministers want the Europe Bill to clear all its Commons passages by the summer recess, getting Royal Assent by the end of the year.
A referendum would then take place in April, May or June of next year. A September 2006 vote has now been clearly rejected.
Nobody in Downing Street would deny that a UK referendum, if it comes, would be a big challenge.
But as one close ally of the prime minister puts it: “If you believe that Europe is going in the right direction and that this constitution helps to streamline the way Europe operates,then you want to see it supported across the Continent.”
If France votes No, the European scene will start to look fractious and messy.
Mr Blair would certainly want to use the British presidency to present himself as a man who can bring Europe back together again.
Whether he could succeed is hard to predict.