Reform has won the Runcorn and Helsby by-election by just six votes, beating Labour after a dramatic recount in the early hours of this morning.
In Sir Keir Starmer's first major electoral test as prime minister, former Conservative councillor Sarah Pochin overturned a 14,696 majority to take the Cheshire seat for Reform.
The by-election was triggered by the resignation of former Labour MP Mike Amesbury, following his conviction for assaulting a constituent.
Reform's first ever victory in a parliamentary by-election came after Labour held on in a string of mayoral races.
It means Reform UK - originally called the Brexit Party when it was founded in 2018 – now has five MPs.
Labour requested a recount after the first tally put Nigel Farage's party ahead by just four votes. The final result beats the previous post-war record for the closest by-election, which was won by just 57 votes in Berwick-upon-Tweed in 1973.
Local council election results in England will also be declared this morning, you can follow them live on the BBC here.