Sadiq Khan has said he would “absolutely” join picket lines in the future but refused to be drawn on the controversial sacking of Labour front bencher Sam Tarry.

The Ilford South MP was sacked from his role as Shadow Transport Minister on Wednesday by party leader Keir Starmer after appearing on a picket line alongside striking rail workers and giving “unauthorised” interviews to the media.

Speaking to LBC Radio on Thursday, the Mayor of London was asked whether he would be appearing on any picket lines in the coming days.

Mr Khan said he would not “simply because of the pressure of work”, but that he “absolutely” would otherwise.

He said: “I have in the past appeared on picket lines and I think it’s really important to make sure we understand that, actually, the genesis of all these problems – the root cause of all these problems – are Government policies.”

The mayor described himself as a “proud trade unionist” and said that trade unions “have been a force for good to our country over the recent weeks, months and years”.

But he refused to be drawn on whether Keir Starmer was right to sack Mr Tarry for his support of striking rail workers this week.

Mr Khan said he has “not had a chance to speak to Sam or Keir” since the incident but said that both are “dear friends”.

He did, though, express sympathy with the former Shadow Transport Secretary over the “boring process point” that led to his sacking and stressed that it was due to not following rules around “collective responsibility” of Shadow Cabinet members rather than appearing on a picket line.

Mr Khan said: “It would frustrate the hell out of me having to stay in my lane and just talk about the area I’m the Minister of and not be able to go outside the policy agreed at Shadow Cabinet or Cabinet. But that’s what being a member of the Shadow Cabinet means, I’m afraid.”

The sacking of Mr Tarry has led to widespread anger among some Labour Party members and trade unionists, who have questioned Mr Starmer’s stance on supporting strikes.

The Labour leader has been accused of hypocrisy after issuing a memo on Monday banning all MPs from attending local picket lines despite previously claiming to be a “proud trade unionist” who had worked with unions “all my life” during his 2020 leadership campaign.

Critics have said that the move is a signal that Labour is abandoning its roots as the party of the working class.

In his response on LBC on Thursday, Sadiq Khan said that there is “no illusion” that the labour movement in the UK “is the Labour Party and the trade unions” and that he was “really proud of that link”, adding that it was his party’s job to “represent ordinary people”.

But the Mayor of London urged Tube workers to “reconsider” plans to strike on August 19 over fears that jobs and pensions could be slashed as part of a long-term funding settlement for TfL offered by the Government.