Jeremy Corbyn has given his backing to striking train drivers on Southern Rail, calling on the Government to re-nationalise the service.
With commuters set for another week of travel misery as members of the Aslef union embarked on three days of industrial action in their dispute over driver-only trains, the Labour leader condemned the company's actions.
Asked on the BBC Radio 4 Today programme if he would join the picket lines, Mr Corbyn said: "Yes I would because I think Southern Rail have behaved in a terrible manner and the Government seem to be more interested in protecting Southern Rail despite its appalling service.
"I would want that franchise brought back into public ownership and the public sector. After all, we provide the rails, we provide the trains and they make the profits from running them."
Despite the prospect of more cancellations and delays, he insisted that many commuters affected by the strike would back his position.
"I think many people who are trying to commute in from Brighton are utterly fed up with Southern Rail and the way that it has behaved," he said.
"People in Brighton and elsewhere tell me how angry they are with Southern Rail and they want the public to intervene. It is up to Government to intervene now and take that franchise back into direct public ownership."
Following Monday's one-day strike on the London Underground, Mr Corbyn said he believed negotiations between Transport for London (TfL) and the unions should have continued.
However he said it was now up to TfL to come forward with a fresh offer to end the dispute over manning levels at Tube stations.
"The strikes have taken place because there was a failure to agree," he said.
"I think what should have happened was a continuation of the negotiations and another offer made by TfL.
"Now we have had the one day of strike, the union has shown its determination to pursue this. I would hope there would now be an agreement on this."