Southern Rail RMT members began a five day strike earlier today, arguing that passenger safety is being compromised by plans for train drivers, rather than guards, to operate doors.
But May has now followed her rail minister in slamming the strikers, with her spokeswoman saying today that the industrial action would “cause more disruption and misery for passengers”.
However, Downing Street said that such a move may make the situation worse for commuters.
A spokeswoman for May said that the government is determined to continue working with Southern owner Govia Thameslink Railway.
“I don't think it is as simple as changing the operator. That would create more uncertainty and risk delaying work that is already underway to improve the service,” they said.
Southern commuters could face a second strike later this summer – the TSSA will ballot staff in September over a similar walk out.