Sir Keir Starmer has responded to Transport Secretary Louise Haigh’s resignation with a strikingly brief reply.

The Cabinet Minister stepped down when it emerged she pleaded guilty to a criminal offence related to incorrectly telling police that a work mobile phone was stolen in 2013.

It is understood the incident was disclosed to Sir Keir when she joined the shadow cabinet.

In a letter to the Prime Minister, she said she is “totally committed to our political project” but believes “it will be best served by my supporting you from outside Government”.

Louise Haigh before appearing on the BBC’s Sunday with Laura Kuenssberg Show (Image: Getty)

In a reply, Sir Keir thanked Ms Haigh for her work to deliver the Government’s transport agenda.

He said: “Thank you for all you have done to deliver this Government’s ambitious transport agenda.

“You have made huge strides to take our rail system back into public ownership through the creation of Great British Railways, investing £1 billion in our vital bus services and lowering cost for motorists.

“I know you still have a huge contribution to make in the future.”

On Thursday evening, Sky News and the Times newspaper reported that Ms Haigh had admitted an offence in 2014 following the incident. She had reported to police the device was stolen when she was “mugged” in 2013.

It is understood that it was a fraud offence and that the conviction is now spent.

Ms Haigh said she discovered “some time later” that the phone had not been taken.

She said the matter was a “genuine mistake” from which she “did not make any gain”, and that magistrates gave her the “lowest possible outcome”.

Ms Haigh has been Sheffield Heeley MP since 2015 and held a number of shadow ministerial and shadow cabinet roles before becoming Transport Secretary when Labour won the election in July. Before she entered politics she spent time as a special constable.

She was working for insurance giant Aviva at the time of the incident, according to the reports.