Mr Tarry was sacked from the frontbench on Wednesday hours after joining strikers at an RMT picket line at Euston station.
A former Labour shadow minister sacked after giving broadcast interviews from a picket line has said he “absolutely” still thinks Sir Keir Starmer is the best person to become prime minister.
Joining another picket line at Paddington station in London on Saturday, the former shadow transport minister said it was “really important” for Labour MPs to show their solidarity with striking workers.
It came as members of Aslef in seven train companies walked out for 24 hours, crippling services in many parts of the country.
Mr Tarry told the PA news agency: “I believe Keir Starmer is absolutely still the best person to become prime minister and I’ll be campaigning every day for a Labour government.”
He added that the Labour Party needed a “fundamental recalibration” of its relationship with the trade union movement and needed to demonstrate it was on their side.
Sir Keir, who previously banned frontbenchers from joining picket lines, said Mr Tarry was sacked for booking himself onto media programmes without permission and making up policy “on the hoof”.
Mr Tarry also appeared alongside former party leader Jeremy Corbyn at a rally for striking BT workers on Friday.
The Labour MP for Ilford South said: “We should never have been in a situation where we had an edict that you can’t join a picket line.
“This is the Labour Party, the clue is in the name.
“We are the party founded by the trade unions.”
He said the link between the union movement and the Labour Party is “indivisible” and “part of the same fabric”.
Mr Tarry added: “For me to be here is about showing that the Labour Party and a massive majority of Labour Party members and MPs do support the striking workers.”
He said he had spoken to several MPs across the country who were backing the workers.