The Rail, Maritime and Transport (RMT) union today said it was holding firm on strike action this week affecting five train networks, after train drivers' union Aslef resolved its long-standing dispute with Southern rail yesterday.
The RMT remains in dispute with Southern rail over the role of the guard, and this week has held walkouts across Southern, South Western Railways, Greater Anglia, Northern and Merseyrail, with action continuing for a second day today on Southern, Greater Anglia and South Western Railways.
The union's general secretary Mick Cash said today members "remain solid and united this morning in separate disputes which are about putting safety, security and access to transport services before the profiteering of these rip-off private rail companies".
Cash added: "On behalf of RMT I repeat the demand that Theresa May and Chris Grayling call off the centrally imposed blockade on serious talks in these disputes and allow us to get on with genuine negotiations with their contractors."
Earlier this week, transport secretary Chris Grayling said the action "can't be about safety", and that the union was calling "political strikes over things that aren't actually happening".
The ongoing row comes as train drivers' union Aslef yesterday brought an end to its drawn-out saga with Southern rail over the introduction of so-called driver-only operated trains, with members voting to back the third deal agreed by their union and the train firm.
They had previously voted down two deals, leaving Aslef and Southern to head back to the drawing board on both occasions.
The agreement includes a five-year pay increase for drivers of 28.5 per cent, and marks a significant step forward for Southern, which had suffered most disruption to its services when the drivers walked out.
Paul Plummer, chief executive of the Rail Delivery Group, representing train operators, said the outcome of the Aslef referendum "leaves the RMT leadership completely isolated".
The RMT however, which predominantly represents conductors, called the settlement a "shoddy deal".
"The result changes absolutely nothing in terms of RMT's campaign for a safe and accessible railway for all," Cash added.