After the three by-elections – in Uxbridge and South Ruislip, Selby and Ainsty, and Somerton and Frome – there will be three new MPs taking their seats in parliament.
The elections took place following the resignations of three Conservatives – Boris Johnson, Nigel Adams and David Warburton.
So who are the new MPs that will be taking their seats in parliament after the summer recess?
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Reaction as Tories hang on in Uxbridge
Labour’s 25-year-old Keir Mather was declared the winner of the by-election in Selby and Ainsty in North Yorkshire.
Mr Mather works as a senior public affairs adviser for the Confederation of British Industry and before that was a parliamentary researcher for shadow health secretary Wes Streeting.
At just 25, he is now the youngest MP in the Commons – replacing Labour’s Nadia Whittome as the so-called Baby of the House.
The Oxford graduate, from Hull, has said his age means he can relate to younger voters who are struggling to get on the housing ladder and facing a lack of economic opportunity.
His campaign centred on the cost of living crisis, public transport and NHS waiting lists, as well as local issues such as flooding and sewage, and anti-social behaviour.
Labour overturned a Conservative majority of 20,137 with his win – the largest majority reversed at a by-election.
Mr Mather won 16,456 votes, compared to the 12,295 cast for the Tory candidate Claire Holmes. This equals a majority of 4,161.
Steve Tuckwell will succeed Boris Johnson as the Conservative MP for Uxbridge and South Ruislip, after a hard fought battle with Labour in west London.
Mr Tuckwell was declared the winner after a speedy recount – but he only secured a majority of 495.
The former postie is a lifelong resident of South Ruislip and has represented the area as a ward councillor since 2018.
He has sought to distance himself from Mr Johnson by focusing his campaign on local issues, declaring the vote a “referendum” on ULEZ – the controversial plan to expand the zone where people have to pay a £12.50 daily fee to drive in London if their vehicle does not meet emission standards.
Mr Tuckwell argues the charge will devastate businesses and cost families up to £4,500 a year.
Lib Dem Sarah Dyke, who lives in the Somerton and Frome constituency that she will now represent, has said her farming family can trace their local roots back over more than 250 years.
She has represented Blackmoor Vale on Somerset unitary council since the 2022 local elections, where she defeated Hayward Burt, CCHQ’s resident expert on conquering Liberal Democrats.
She holds the council’s portfolio for the environment and climate change.
She was selected as the party’s prospective parliamentary candidate back in May 2022.