Political Correspondent Libby Wiener explains why some factions of the Labour party have been angered by the sacking
Sir Keir Starmer is under fire from the left of Labour after sacking a frontbencher who joined striking rail workers on a picket line.
The Labour leader has defended his move to sack ex-shadow transport minister Sam Tarry, saying he did so because the MP booked media appearances without permission and "made up policy on the hoof".
"That can't be tolerated in any organisation because we've got collective responsibility," Sir Keir added as he explained the sacking to journalists.
But left-wing MPs, including former shadow home secretary Diane Abbott, and a number of trade unions are said to be furious about it.
Ms Abbott said the sacking was "quite shocking" and questioned whether his policy of banning frontbench MPs from picket lines will help him beat the Tories in an election.
The veteran Labour MP refused to say Sir Keir could be removed as leader over his stance on picket lines but said major trade unions, which fund the party, are taking it "very seriously".
"Keir needs to listen to ordinary Labour supporters," she said. "And he needs to stop distancing himself from trade union members. There are seven million trade union members in the country. Labour can't win without them and he needs to pay attention to that."
She added: "At this point I believe that Keir will lead the party into the next election but he has to start paying attention to ordinary Labour supporters and ordinary trade unionists."
"He will be the first Labour leader ever to stop MPs going on picket lines and I think he needs to stop and think whether this is really a vote winning strategy," the Hackney MP concluded.
Asked if Mr Tarry was removed from the Labour frontbench for appearing on a picket line, Sir Keir said during a visit to Birmingham: "Sam Tarry was sacked because he booked himself onto media programmes without permission, and then made up policy on the hoof, and that can't be tolerated in any organisation because we've got collective responsibility.
"So that was relatively straightforward. Of course, as far as the industrial action is concerned, I completely understand the frustration of so many working people who've seen the prices go up, seen inflation through the roof, and their wages haven't gone up.
"So the Labour Party will always be on the side of working people, but we need collective responsibility, as any organisation does."
Mr Tarry stood alongside striking workers at London's Euston station on Wednesday morning, despite Sir Keir's orders to stay away from the demonstrations.
He told ITV News it was a "shame" to be sacked for "standing shoulder to shoulder" with rail workers and his former colleagues, and suggested his party must support strikers if it is to beat the Tories in a general election.
"I think that we are going to really struggle to win the faith of the British people over the next few months and into general election when doctors go on strike, when nurses go on strike, when barristers and university lecturers," he said.
Unions were quick to express their disquiet about Mr Tarry's sacking. Transport Salaried Staffs' Association (TSSA), RMT and Unite all condemnded Sir Keir's decision.
The TSSA said it was "ashamed" of the Labour Party, which Sir Keir is "not worthy" of leading.
It dismissed Labour's "excuses" and called on the party to "wake up and smell the coffee", insisting it won't win an election by "pushing away" seven million trade union members.
“We expect attacks from the Tories, we don’t expect attacks from our own party," said the TSSA in a statement.
"As a Labour-affiliated union, our union is ashamed of the actions of the Labour Party leadership and the anti-worker, anti-union message it is sending out.
"This is a bad day for our movement. And if Keir Starmer doesn't understand the basic concept of solidarity on which our movement has been built then he is not worthy of leading our Party.”
Unite the Union said Labour under Sir Keir is becoming irrelevant to working people but the leader said his party has a "strong relationship" with the organisation.
"I am a member of the Unite union. That relationship is historic, it is present, and it will be the future of the Labour Party," he said.
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A number of backbench Labour MPs also joined picket lines, including Liverpool West Derby MP Ian Byrne, Brent Central MP Dawn Butler, Birmingham Hall Green MP Tahir Ali, Gateshead MP Ian Mearns and South Shields MP Emma Lewell-Buck.
Sir Keir said Labour is taking "each case as it comes" on shadow ministers joining picket lines.
He was asked if it would be allowed for a shadow minister to appear on a picket line during Saturday's next strikes if they did not make any unauthorised media appearances.
Speaking in Birmingham, Sir Keir responded: "We take each case as it comes. I want to see these issues resolved.
"And my criticism is really of the government because it's inevitable, I think, when you've got a cost-of-living crisis, that so many working people are concerned about their wages. I understand that, I understand the concerns."