Two days on strike, three days working normally: that is the pattern set by French rail workers for spring and early summer.

The unions are opposed to the labour reforms being implemented by President Macron’s government. Transport workers in France currently have generous guarantees on employment protection, pay rises and retirement.

The series of rolling two-day strikes begin just after Easter, on 3 April, and continue until 28 June. A union leader has described the dispute as “an intense and long-lasting conflict”.

The strikes are likely to cause hundreds of cancellations each day on a wide range of trains from Paris commuter services to TGV expresses.

SNCF, the national train operator, has stopped selling tickets for long-distance trains on planned strike days in April.

Some observers have likened the proposed action to a bitter strike in 1995, which brought France’s rail network almost to a halt until the prime minister, Alain Juppe, backed down on modernisation plans.

As a taste of what lies ahead, staff working for SNCF plan to strike from Wednesday 21 March and 7am on Friday. Advance tickets for 22 March have been taken off sale.

Union members working for RATP, which runs public transport in Paris, are also likely to stop work on Thursday.

Kate Andrews, co-founder and chief operating officer of Loco2, the train booking service for the UK and Europe, said: “This is a frustrating time for everyone involved, and it's our role to do everything we can to support passengers and promote the benefits of train travel.

“For passengers who can be flexible on the day of travel, it may be possible to exchange SNCF tickets for an earlier or later service at the station. Trains may be busy and seat reservations can't be guaranteed during strike action.

“In the event of a delay, passengers should seek to have their ticket validated by a member of station or train staff as proof of delay as this will help ensure they can travel on subsequent connecting services.”