The candidate for Reform U.K., the right-wing party of British lawmaker and ally of President Donald Trump, Nigel Farage, won a parliamentary by-election by six votes, taking the seat from the governing Labour Party in a stunning political upset.

Local elections in England have seen significant gains for Reform UK as both the country's main political parties have suffered.

Nigel Farage has now issued a seven-word warning to Brits, giving voters a snapshot into what Reform will do with its new power.