Read Charles Bremner's Paris blog

Travellers face long delays in France today when transport workers stage a one-day stoppage after striking fishermen blocked Channel ports and disrupted petrol supplies for a day.

Railway, Paris Métro and air controllers’ unions are joining a 24-hour protest by civil service and private sector unions against a move by the Government to raise the retirement age by a year. Domestic rail services will be partially disrupted but Eurostar cross-Channel trains are expected to run on time. Only minor delays are expected to flights at Paris airports.

In a separate action, Channel ferries came to a near-standstill yesterday after about a hundred fishing craft joined a national port blockade, obstructing terminals in Calais, Boulogne and Dunkirk harbours. The fishermen later halted their action after President Sarkozy offered ¤

The strikes are the latest in a series of protests against Mr Sarkozy’s reforms, which have until now focused on the public sector. The President has taken direct command of daily government after turbulence in his parliamentary party and tension with François Fillon, his Prime Minister.

The action by fishermen demanding more state subsidies for their diesel led to fuel depots around Marseilles and on the Atlantic coast being blocked. A run on petrol stations led to shortages around Montpellier, on the Mediterranean, and the port of La Rochelle. Lorry owners’ unions threatened to stage protests if they were not given more aid to offset rising fuel costs.

Four policemen were injured in clashes with fishermen in Paris, where hundreds marched on the Agriculture Ministry, firing distress rockets at riot police. “Sarkozy — liar” was a common chant among the protesters, who say the President has failed to fulfil a promise of assistance. The Government had promised a ¤310 million (£249 million) aid package after the November blockades. Since then the price of diesel, which is taxed lightly for fishermen, has almost doubled.

Mr Sarkozy promised again on Tuesday to provide more aid but a further package is likely to run into opposition from the European Commission, which is only just approving the last one. Experts and media commentators say that subsidies are not a long-term solution and that the fishing industry must modernise itself in the way that the Spanish, Portuguese and other neighbours have done.

Despite the protests, many French continue to support most of the reforms that Mr Sarkozy promised in his election campaign last year, opinion polls show.

The strike today is a protest against a plan to extend the period in which people must work before they retire on full pension from 40 years to 41.

That effectively means raising the average real retirement age of 58 by a year.

The biggest source of discontent is the rising cost of living. The President is deemed to have reneged on his campaign promise to put more money in French pockets. He took comfort this week from figures showing that employers were increasingly taking up his scheme to allow people to “work more to earn more”. This allows people to work tax-free overtime beyond the 35-hour maximum working week.

Mr Sarkozy told the Cabinet yesterday that he had no plans to scrap the short official working week, despite pressure from leaders of his own Union for a Popular Movement.

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