Mr Tarry was seen on Wednesday supporting striking rail workers – in direct contravention of an order from Sir Keir Starmer not to do so.
Acting decisively, Sir Keir has overseen Mr Tarry's dismissal.
A Labour Party spokesperson said: “The Labour Party will 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 frontbench 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 frontbench.”
Sam Tarry and Sir Keir Starmer PA
RMT general secretary Mick Lynch speaks at a rally outside Kings Cross station, London Dominic Lipinski
Mr Tarry said he is “proud” to stand with striking rail workers.
In a statement, he said: “These key workers kept our train services running throughout the pandemic, and were among Britain’s Covid heroes alongside the NHS and other public services.
“Those same workers have been forced to take action because they’re faced with a cost-of-living crisis and rampant inflation caused by the Government’s mismanagement of our economy, leaving millions struggling to pay their bills and provide for their families, made worse by the fact that callous and incompetent ministers refuse to even negotiate with their trade unions.
“This dispute would not be taking place under a Labour government, which would ensure that rail workers receive a fair wage.
“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.”
Mr Tarry was not the only Labour MP to defy Sir Keir, though.
Brent Central MP Dawn Butler, Birmingham Hall Green MP Tahir Ali, Gateshead MP Ian Mearns and South Shields MP Emma Lewell-Buck were among those sharing photos of themselves on social media from picket lines.
And Jeremy Corbyn, the former party leader and now independent MP, said: “There are three Labour MPs here on this picket line, and no doubt there are all over the country.
“I think Members of Parliament represent their constituencies and hear day to day what their constituents want, and they’re doing the right thing by being there with the workers in dispute.”
Strike action has continued to disrupt the lives of passengers across the UK, as one woman set to miss her uncle’s funeral said the situation has left her feeling “less of a part of my family”.
Members of the Rail, Maritime and Transport (RMT) union at Network Rail and 14 train operators took industrial action on Wednesday in a row over jobs, pay and conditions.
Travellers described being “angry” and “distressed” as an autistic man missed his first day at a new job and one woman was forced to watch her uncle’s funeral remotely.