Rail union the RMT has urged train operators to think again on plans to remove guards from their services in the light of the General Election result.
General secretary Mick Cash has written to Northern Rail, which operates services across Lancashire, as part of the plea.
He says the public, through the unexpected surge in votes for Labour, has sent a clear message and the Conservative Government, led by Theresa May, has 'no mandate for diluting safety'.
The RMT has already staged several walkouts at Northern as part of an ongoing dispute over the introduction of 'driver only' services.
Mr Cash said: “This election has sent out the clearest possible message that the British people have rejected the Tory programme of cuts, austerity, privatisation and division.
"RMT is calling for an immediate halt to the push to axe the guards on our trains.
"That was a political policy driven by the Tory Party and should now be buried under the weight of votes that have racked up against Theresa May and her programme. There is no mandate for diluting safety on our transport services.
"RMT will be writing to Northern, Southern and Merseyrail today demanding that they lift the threat to the guards on their trains and we expect them to do that in light of this election result with immediate effect.
"This is just a staging post in the unstoppable drive towards the full public ownership of our transport services."
Northern, which is operated by Arriva - itself a subsidiary of German-state railway Deutche Bahn - has committed to half of its services becoming driver only operated by 2022.
The company says a second member of staff will still be deployed on most trains.
However, unions are concerned about changes to the 'safety critical' aspects of their work.
During strikes, held in March, April and May, Northern was able to operate around half its normal timetable.
Similar disputes at Merseyrail and Southern have created significant disruption.
The union's last proposed strike, on May 30, was cancelled in the wake of the Manchester Arena bombing.