The Speaker of the House of Commons made the joke after Labor’s Keir Mather swore an oath of allegiance to the king as Parliament returned from summer recess on Monday.
At 25, Mr Mather is now the youngest MP in the Commons – the baby of the House – after overturning a Conservative majority of 20,137 and winning the North Yorkshire seat for Sir Keir Starmer’s party.
He received 16,456 votes ahead of Conservative Claire Holmes, who received 12,395 votes.
The by-election was called when incumbent Tory Nigel Adams resigned as MP.
After winning the by-election in July, Mr Mather said: “It is the privilege of a lifetime to be elected Labor MP for Selby and Ainsty.”
“Together we made history and gave our community a new beginning.
“Now it’s time for a new beginning for Britain.”
Mr Mather was followed by Conservative Steve Tuckwell, who took the oath of allegiance.
He held the seat of Uxbridge and South Ruislip for the Tories following the dramatic resignation of former Prime Minister Boris Johnson.
Liberal Democrat Sarah Dyke also took her seat on Monday after winning Somerton and Frome.
She succeeds former Tory MP David Warburton after he resigned after admitting cocaine use.
The three newcomers are at the start of a busy period in politics, with the party conference still weeks away, the King’s speech taking place and two more election campaigns looming.
Labor and the Liberal Democrats are both vying to secure a 24,664-strong majority in former Tory culture minister and Johnson ally Nadine Dorries’ mid-Bedfordshire seat.
Prime Minister Simon Hart requested that the decision to trigger the by-election be postponed to September 12th.
Meanwhile, a battle for the Rutherglen and Hamilton constituency sparked by former SNP MP Margaret Ferrier’s breach of Covid-19 rules is being fought hard by Labor and the SNP.
The SNP’s Owen Thompson filed the lawsuit on Monday to launch the contest.
By-elections must take place between 21 and 27 working days after the election notice is issued, suggesting the contest between Rutherglen and Hamilton could take place on October 5 and Mid Bedfordshire in mid-October.
https://www.yorkpress.co.uk/news/23766745.new-selby-mp-keir-mather-takes-seat-house-commons/?ref=rss New Selby MP Keir Mather takes his seat in the House of Commons