Members of shadow cabinet surprised by Labour chancellor’s presence on picket line after Heidi Alexander said party was not supporting industrial action

The shadow chancellor, John McDonnell, joined a junior doctors’ picket line despite Labour having agreed that the party would not endorse the strike.

Members of the shadow cabinet were surprised to find McDonnell join the protest at St Thomas’ hospital, near the Houses of Parliament, shortly after Labour’s health spokeswoman Heidi Alexander had explained to them that the party would stand by its policy of not supporting industrial action.

“Eyebrows were raised when John McDonnell turned up at the picket line shortly after he had heard from Heidi at the meeting of the shadow cabinet,” one Labour source said. McDonnell had raised no objections when Alexander outlined the party’s stance.

McDonnell made no intervention during Alexander’s presentation in which she said that Labour was strongly sympathetic to the junior doctors and that the health secretary, Jeremy Hunt, had, in the words of one shadow cabinet member, “ballsed it up”. Other members agreed when Alexander said Hunt should return to the negotiating table but she made clear that Labour would not be endorsing the strike.

Alexander was talking to the Labour leader, Jeremy Corbyn, at the end of the meeting when McDonnell put on his coat to walk across Westminster bridge to visit the striking junior doctors at St Thomas’. McDonnell gave an interview to the BBC outside the hospital which was supportive of Alexander’s position.

He said: “All these junior doctors are asking for is Jeremy Hunt to get back to the table at [the negotiating service] Acas and resolve this. In Scotland and Wales, they’ve been able to introduce the seven-day working without industrial action. I can’t understand why that is not happening in England. These people don’t want to go on strike. They want to look after their patients. We are just saying to Jeremy Hunt: get back round the table now.”

But some Labour sources said McDonnell’s decision gave the impression of party support. “It is Labour’s approach that we don’t endorse industrial action,” one source said.

McDonnell has told colleagues that he was simply responding to a request to visit the doctors. His visit was all above board, he believes, and was agreed with Alexander.

The strong reaction to McDonnell’s decision highlights the difference him and Corbyn – who both regularly supported strikers in their years on the backbenches – and shadow ministers. Former ministers believe that Labour could suffer severe political damage if it endorsed strikers.