Lord Pearson of Rannoch has been elected as the new leader of the UK Independence Party (Ukip).
The former Conservative peer secured 48 per cent of the vote in a ballot of party members. Around 9,900 votes were cast.
Lord Pearson, 67, replaces Nigal Farage MEP, who is stepping down in order to focus on his work in Brussels and securing a Westminster parliamentary seat.
Farage is to challenge Commons Speaker John Bercow in his Buckingham constituency at the next election.
Lord Pearson was made a Conservative peer in 1990, but had the Tory whip withdrawn in 2004 after suggesting voters should vote Ukip in elections that year.
He recently invited right-wing Dutch politician Geert Wilders to Britain to screen a controversial film about Islam.
Speaking after his victory Lord Pearson said: "Ukip is not for sheep, Ukip is not for lemmings. Ukip is for people who think and act for themselves.
"And it is for people who now for many years have seen through the lies of our political class and our main political parties, particularly in regard to our relationship with the European Union.
"If you want to go on being deceived by the main parties, then stay in them and vote for them.
"If you don't, the only way forward now is Ukip. It is the only show in town."
Lord Pearson is the first peer to lead a British political party since the Earl of Home became Conservative party leader and prime minister in 1963.
He immediately declaimed his peerage, becoming Sir Alec Douglas-Home.
Two weeks later he entered the Commons as MP for Kinross and Perthshire after a by-election.
Dods Parliamentary Communications Ltd