The terrorist attacks of 13 November have had an enduring effect on people living in Paris and France’s other big cities. Hotel bookings and restaurant reservations are down, and some people will no longer go out in the evening. There have been several other minor terrorist outrages across the country since November, and tension — prompted by repeated government warnings — remains high. The campaign for the 2017 presidential elections will start in July, but François Hollande’s popularity, which soared after the Charlie Hebdo attacks a year ago, has been sliding again.

Hollande’s polls rose slightly after he declared a state of emergency on 14 November. During a state of emergency, the French government assumes fearsome powers that are normally only exercised in time of war. It can suspend daily life without the usual legal authority. In the interests of public safety, a minister can, without justifying his decision, ban meetings and demonstrations, search private property, close business premises, impose a curfew and even order house arrests. The period of emergency has just been extended and is now due to last until the end of May.

This decision is not universally popular, although it has general public support. It has been strongly opposed by the political left and is due to be debated next week in the National Assembly. Leading the protests is France’s Human Rights League (Ligue des Droits de l’Homme, or LDH) which argues that the extension is unjustified on security grounds and that it is a political move intended to pre-empt criticism of the government in the case of further attacks. The LDH petition has been signed by more than 400 university teachers, by many law professors, by one of the police unions and by the judges’ union.

The growing opposition to the state of emergency is only one of the problems faced by Hollande and his prime minister Manuel Valls as they struggle against Islamist terrorism. And the curious thing is that most of the criticism is not coming from their political opponents but from their own supporters.

In another anti-terrorist move, President Hollande decided at the end of last year to introduce a law that would enable him to strip anyone convicted of terrorist offences of their French nationality, provided they had a second nationality to protect them from becoming stateless. ‘Anyone who commits an act of terrorism against France excludes himself from the pacte républicain,’ according to prime minister Valls. This idea, known as la déchéance, was originally thought up by leaders of the official opposition party — the Republicans, under ex-president Nicolas Sarkozy — and was warmly supported by the far-right Front National.

In an atmosphere where even government supporters are demanding more ‘order’, ‘authority’ and ‘repression’ — and some are even demanding the reintroduction of the death penalty — Mr Hollande was hoping he would wrongfoot his opponents and demonstrate his determination to protect the people of France. Unfortunately for the president, such a law requires an amendment to the constitution of the Fifth Republic — and constitutional amendments require a majority in both the National Assembly and in the Senate. Since many members of his own Socialist majority in the Assembly once again oppose the amendment, the president can only get this bill passed with the support of the opposition.

Just before Christmas, the last remaining influential left-winger in the government, the minister of justice, Christiane Taubira, who was an outspoken opponent of la déchéance, announced that the president was ready to drop the idea. This news delighted many on the left, but was promptly denied by a government spokesman. Last week Madame Taubira finally resigned. It had become obvious that she had lost an arm-wrestling match with the prime minister and that her influence over the president was at an end.

Her departure left Mr Hollande isolated within his own party and his left-wing members counting the days to electoral defeat. Madame Taubira has now published a closely argued pamphlet setting out her objections to the constitutional amendment in corrosive terms as ‘an empty symbol’ that breaches the principle of égalité, creating two classes of citizens and two classes of terrorists. She can now be expected to lead the Socialist opposition to an amendment that will be proposed by the prime minister.

But that is not the end of the problems faced by the increasingly unpopular Manuel Valls. He has also managed to fall out with an entirely different constituency in the grand coalition that makes up the French left. Before he became prime minister, Mr Valls was, among other things, the mayor of Évry, a new town 15 miles to the south of Paris. In that role he was one of the most ferocious critics of the Muslim ‘headscarf’, which he banned not only in schools but in any public place and even for mothers taking part in school outings. His hardline attitude stemmed from his personal commitment to la laïcité (secularism), the principle of total separation between church and state.

Last month Mr Valls publicly rebuked the country’s chief secularist, Jean--Louis Bianco, for not being fully committed to the cause. Mr Bianco, who is the president of the ‘Secular Observatory’, an umbrella organisation that keeps watch over the movement’s interests, had supposedly blotted his copybook by agreeing to join religious leaders in a public appeal for mutual understanding and tolerance. Mr Bianco, an ex-minister who was the highly influential secretary-general at the Elysée under President Mitterrand, does not have a very high opinion of Mr Valls and issued a furious rebuke in his turn, accusing the prime minister of supporting a small group of ‘secular fundamentalists’ who threaten civil harmony and undermine his own attempts to strengthen national unity by building bridges between long-standing opponents.

The battle between secularists and their religious opponents in France breaks out at regular intervals and usually involves education. Its extension into the area of national security is potentially very dangerous. Now the squabble between secularists has revealed serious cracks in one of the pillars of the country’s unwritten social contract. The fanatical intolerance shown by Mr Bianco’s humanist critics recalls the revolutionary slogan of 1792, ‘Be my Brother, or I kill thee!’ — and shows that some of the pharisaical spirit of the Enragés and the Committee of Public Safety lives on.

But with the Islamic community facing a sharp increase in racist incidents, and the chief rabbi of Marseilles advising his congregation not to wear their skull caps in the street, all that ‘secular fundamentalism’ seems to have achieved to date is to unite Catholic, Jewish and Islamic leaders in a new alliance against a common enemy.

During a state of emergency, the French government assumes fearsome powers

Patrick Marnham is a former literary editor of this magazine and a former Paris correspondent of the Independent.