President Sarkozy faces a make-or-break week in his stand-off with French unions, with the industrial unrest that has paralysed the country’s transport network set to spread to schools, hospitals, the Bank of France and even the weather office.

With universities shut down and the rail system in chaos, public sector workers will add to the tension when they strike over pay and job cuts tomorrow. However, Mr Sarkozy will draw comfort from signs last night that union leaders are looking to convince their militant membership to accept a negotiated end to the stoppages.

As the Finance Ministry gave warning that the turmoil is costing €400 million (£285 million) a day, the six unions at the forefront of the movement said that they would participate in talks with SNCF, the state railway network, on Wednesday. The Government said it would join the talks only if the trains started running.

Mr Sarkozy was bolstered as about 6,000 of his supporters marched through Paris yesterday to demand an end to the strikes and to call on him to stand firm. Sabine Herold, spokeswoman for Alternative Libérale, which organised the demonstration, said: “We have two messages. The first is . . . they’ve got to stop blocking the whole country to defend their own egotistical interests. The second is to give a kick up the Government’s backside. We need real reforms. It must go much further.”

The main dispute is over the President’s pledge to end the generous pensions rights that enable railway workers, Métro drivers and opera musicians to retire well under the age of 60. With 26 universities totally blocked and 30 more facing partial blockages by students opposed to a law to decentralise the higher education system, the radical Left is hoping to push Mr Sarkozy into abandoning his reform programme.

At a meeting last night the union leaders promised more transport strikes today. But their decision to participate in Wednesday’s round-table at SNCF will be seen as an olive branch. The talks will focus on ways of compensating workers for loss of pension rights. Guillaume Pépy, the managing director of SNCF, said more and more railway staff were returning to work.

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