On the eve of the second anniversary of the Southern Railway dispute over the role of guards, a furious row has broken out after the train operator claimed support for strikes has collapsed.

Charles Horton, chief executive for the franchise holder, GTR, told The Independent: “Seventy per cent of the staff affected by those disputes are now coming to work on a strike day.

“Only a handful of services don’t run on a strike day.”

But the RMT’s general secretary, Mick Cash, responded angrily, saying: “It is simply not true that our members are working on strike days and that is just another slur against Southern staff by a management that has declared war on passengers and the workforce alike.”

The row between Southern and the RMT union over “driver-controlled operation” of trains is Britain’s longest-running industrial dispute. The first strike started at 11am on 26 April 2016.

At the time, Mick Cash said: “This dispute is about safety and the safety-critical role of the guards on Southern trains.

“The company, with an eye on ever-fatter profits, is prepared to axe the guards on some of the most overcrowded and potentially dangerous services in Britain so that they can squeeze every last penny out of their passengers regardless of the consequences.”

In the past two years, RMT members working for the train operator, which mainly covers south London, Surrey and Sussex, have stopped work on 40 days. Many commuters say the strikes have caused profound disruption for their work and home lives.

Disputes about the same issue have since spread elsewhere in Britain, on train operators including South Western Railway, Northern and Greater Anglia.

The Rail Delivery Group (RDG), representing train operators and Network Rail, says that more than half of passenger journeys on Britain’s railway are made on trains where the driver controls the doors. The practice prevails on two other parts of the GTR franchise, Thameslink and the Gatwick Express.

In a one-day Southern stoppage last month, The Independent reported that the only affected lines appeared to be off-peak services between Clapham Junction and Watford Junction, some Southern trains serving Guildford and the Brighton-Hove shuttle service.

Mr Horton urged the RMT union to “get back to running trains for passengers”, saying: “Passengers want to see that, I think our employees want to see that, I certainly want to see that. It is time to call time on this.”