Sam Tarry, the shadow transport minister, was fired after defying Sir Keir Starmer’s ban on appearing at the demonstrations and standing alongside striking workers at London’s Euston station on Wednesday morning.
Ilford South MP Sam Tarry attended the protest at London's Euston station despite Sir Keir telling his frontbench MPs to stay away.
Following the move, union bosses warned the party would be unable to win back Red Wall seats in a general election if it fails to “identify with working class people’s needs.”
MP for York Central, Rachael Maskell, called for the Labour leader to visit picket lines on Wednesday night, while GMB general secretary Gary Smith said it was a “huge own goal” for Labour to “turn a Tory Transport crisis into a Labour story”.
Transport Salaried Staffs Association (TSSA) General Secretary Manuel Cortes said the union was “ashamed” of Labour and suggested it was “deluded” to think the party could defeat the Conservatives without the support of union members.
Mr Cortes said: “Sam is one of us. He grew up in the trade union movement and trade unionism is in his blood. Today Sam did the right thing and stood shoulder to shoulder with rail workers striking for fairness and safety at work.
“Whatever excuses the Labour Party makes about the reasons for Sam being sacked, the reality is that Sam has shown solidarity with his class and we applaud him for that.
“The Labour Party needs to wake up and smell the coffee.
“If they think can win the next general election while pushing away seven million trade union members, they are deluded.
“We expect attacks from the Tories, we don’t expect attacks from our own party.
“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.”
Mr Cortes hit out directly at Sir Keir, adding he was not “worthy of leading” the party if he could not understand “the basic concept of solidarity”.
RMT boss Mick Lynch told Times Radio that Labour would only be able to reclaim its traditional heartlands if it could “identify with working class people’s needs and their campaigns”.
He too attacked the Labour leader, accusing Sir Keir of “playing up to the agenda of Liz Truss and the right wing press.”
Mr Lynch said: “I think (it’s) a bit of an outrage and I think many Labour Party members, union activists and people are looking for a change.”
He added: “If (Sir Keir) can’t identify with that then he’s got no chance of winning back those seats and therefore he’s got no chance of being Prime Minister.”
Unite general secretary Sharon Graham said the move would be “laughable if it were not so serious”.
Ms Graham said: “The Labour sacking of Sam Tarry for supporting working people on strike, against cuts to their jobs and pay, is another insult to the trade union movement.
“Quite frankly, it would be laughable if it were not so serious.
“At a time when people are facing a cost of living crisis, and on the day when the Conservative Government has launched a new wave of attacks on the rights of working people, the Labour Party has opted to continue to indulge in old factional wars.
“Labour is becoming more and more irrelevant to ordinary working people who are suffering. Juvenile attacks on trade unionists will do absolutely nothing to further Labour’s prospects for power.”
In a statement, Labour said it would "always stand up for working people fighting for better pay, terms and conditions at work".
"This isn't about appearing on a picket line. Members of the front bench sign up to collective responsibility. That includes media appearances being approved and speaking to agreed frontbench positions.
"As a government in waiting, any breach of collective responsibility is taken extremely seriously and for these reasons Sam Tarry has been removed from the front bench."
In a statement, Mr Tarry said: “It has been a privilege to serve on Labour’s frontbench for the past two years and to have had the opportunity to speak up for hard-pressed workers who deserve so much better than the treatment they’ve received from this corrupt and out-of-touch Government.
“I remain committed to supporting the striking rail workers, and campaigning for a Labour victory at the next general election, which I will fight for relentlessly from the backbenches.”
Sir Keir Starmer will meet with community leaders in Birmingham today and attend the opening ceremony of the Commonwealth Games as debate continues over the sacking.