Nigel Farage claimed that former House of Commons speaker John Bercow tried to ‘overturn’ Brexit, in his first speech since becoming MP.
The leader of Reform UK is the new representative for Clacton and will be joined in parliament by four others from the party.
Before last week’s general election, Mr Farage had sought to become an MP several times without success.
He was, however, a member of the European parliament for 20 years, during which time he campaigned fiercely for the UK to leave the EU.
Reform came second in 98 seats in the 2024 election, many of which are now held by Labour, and Mr Farage has set his sights on the new government, saying it “could be in trouble pretty quickly”.