John McDonnell today declared he backs workers' rights to walk out as he was grilled over "sympathy strikes".
Asked about whether he backed 'solidarity action' - a practice which was banned under Margaret Thatcher - the Shadow Chancellor said three times he will ensure people have the right to withdraw their labour.
Asked a fourth time by the BBC, he then said clearly "we're not" going to return to sympathy strikes under a Labour government.
However, sources close to Mr McDonnell later did not rule out the possibility of him backing sympathy strikes - which are officially known as secondary picketing.
Instead sources pointed to the Conventions of the International Labour Organization. Some say they convey a right to sympathy strikes, but the European Court of Human Rights has ruled in the past that that right is not "clearly defined".
It comes after Labour figures previously indicated they would repeal Thatcher's ban on sympathy strikes - workers in one sector walking out in solidarity with workers from another.
Jeremy Corbyn said in January 2016: "Sympathy action is legal in most other countries. It should also be legal here."
Labour's 2019 manifesto does not explicitly mention sympathy strikes but says the party would "remove unnecessary restrictions on industrial action."
Mr McDonnell was asked about the issue by BBC Radio 4 host Nick Robinson.
Mr Robinson asked: "Do you still want to restore secondary picketing?
"The idea that workers who are not involved in industrial action can go somewhere else to support people who are.
"Is that what you mean by repealing the anti-union Thatcher legislation?"
Mr McDonnell replied: "We’ll make sure that people have the right as in ILO conventions to withdraw their labour, yes. But let’s be clear -"
Mr Robinson interrupted to ask a second time: "So people can close down a school or a hospital in sympathy with the rail unions for example?"
Mr McDonnell replied: "People will have the right to withdraw their labour but let’s be absolutely clear.
"What we’re doing now via these structural reforms is making sure everyone has a vested interest in the operation of their company or their public utility.
"Sitting on the board, having worker representatives —"
Mr Robinson then asked a third time: "Forgive me, I want to talk about picketing because you’ve raised it and you’ve just confirmed it there.
"Do you think, for example, trade unions on the railways should be allowed to go on strike in sympathy with trade unions running hospitals?"
Mr McDonnell replied: "I believe any worker should have the right to withdraw their labour, but the reality is -"
A fourth time, Mr Robinson asked: "So we could return to secondary picketing?"
Mr McDonnell then replied: "No we’re not.
"We’re creating a new climate in this country which is based upon a stakeholder economy."
