New Labour MP Keir Mather joked that he had “heard far worse” when asked how he felt about becoming “the Baby of the House”.

The 25-year-old will become the youngest MP in the Commons after overturning a 20,137 majority in the North Yorkshire constituency of Selby & Ainsty.

In a speech after he was declared the winner of the by-election, Mr Mather said he “understood the enormity of what has just happened”.

“We have rewritten the rules on where Labour can win. People have opened their doors to us and embraced our positive vision for the future,” he said.

(PA Graphics)
(PA Graphics)

“The people of Selby & Ainsty have sent a clear message. For too long, Conservatives up here and in Westminster have failed us, and today that changes.

“Over the past few months, speaking to hundreds of people on the doorstep, I’ve encountered so much hardship. Hardship made worse by 13 years of negligence and complacency from the Conservatives.”

Speaking after the results were announced from the count at Selby Leisure Centre, Mr Mather told reporters: “As a young person in politics, I really hope to be a representative for the power that young people have to make a difference.”

Asked about whether he could fully understand voters’ concerns at the age of 25, he said: “Well, I’m a taxpayer too, I feel the pressures like anyone else.”

Mr Mather said his first priority would be setting up financial support centres in the constituency, for people to get expert help with issues including mortgage payments and energy bills.

He told journalists that he supported Labour leader Sir Keir Starmer’s policy of keeping the two-child benefit cap, saying: “I think we’re going to inherit an absolute economic mess from the Conservatives when we take power and we’re going to have to make extremely difficult decisions once we do, and I support the Labour government in doing so.”

Mr Mather said the cost-of-living crisis was the number one issue on the doorstep throughout the campaign.

Asked if people were voting for Labour or against the Tories, Mr Mather said: “Well, I make no bones about it, I think local residents were extremely frustrated at the way the Conservative MP (Nigel Adams) stepped down, but they only voted Labour to the extent that they did because they knew we had a plan that would actually deliver on their concerns.”

After Mr Mather’s speech, defeated Conservative candidate Claire Holmes left the venue without talking to reporters.

Labour have said Mr Mather was born in Hull and grew up near Selby, before going to Oxford University.

(PA Graphics)
(PA Graphics)

The party said he has most recently worked as a senior public affairs adviser for the Confederation of British Industry and was formerly a parliamentary researcher for Wes Streeting from 2019 to 2020.

His candidacy was supported by the GMB and Unison unions.

In a jibe at Mr Mather’s age, Conservative MP Johnny Mercer said he had “been at Oxford University more than he has been in a job”.

Speaking on Sky News, Mr Mercer said: “I think we mustn’t become a repeat of The Inbetweeners, you have got to have people who have done stuff.”

He added: “You put a chip in him there and he just relates Labour lines.”