Britain's populist U.K. Independence Party chose European Parliament member Paul Nuttall as leader on Monday, replacing the charismatic but divisive Nigel Farage.
In his parting speech, Farage claimed the political upheavals that are taking Britain out of the European Union and Donald Trump into the White House are far from over.
He said UKIP's anti-EU, anti-globalization politics had had a "seismic" effect in Britain, and beyond.
"It is Brexit that directly led to the Establishment getting beaten on the 8th of November and Donald J. Trump about to take the presidency," Farage said, referring to the U.S. presidential election. "We were the inspiration behind much of that."
Nuttall decisively beat two other contenders in a contest to head the right-wing anti-EU party, winning 62.6 per cent of the votes cast.
The 39-year-old former college history lecturer vowed to unite the fractious party and fight to ensure that Britain's divorce from the EU is not watered down during negotiations.
"We will hold the government's feet to the fire electorally and ensure that Brexit really does mean Brexit," he said.
Monday's announcement follows a tumultuous period for UKIP, which was instrumental in forcing Britain's Conservative government to hold a referendum on EU membership.
The June 23 vote to leave the bloc was a triumph for the party, which was founded to get the U.K. out of the EU. But UKIP's leadership — a collection of authoritarians, libertarians and former Conservatives — soon descended into squabbling.
Farage stepped down after the EU vote, which he said capped his political career. But replacement Diane James resigned after 18 days. The favourite to replace her, Steven Woolfe, also quit after a fight with a UKIP colleague that left him hospitalized.
UKIP won almost 4 million votes in the 2015 election, though that translated into just one of the 650 seats in Parliament because Britain doesn't have a system of proportional representation.
Nuttall said that as leader he would take on the left-of-centre Labour Party in England's former industrial heartlands.
For decades, Labour has been the main party of working-class voters. But, like Trump, UKIP has won the support of many lower-income voters by linking immigration and globalization to the financial squeeze felt by many families.
"I want to replace the Labour Party and make UKIP the patriotic voice of working people," Nuttall said.
Despite its success shaping the political agenda, UKIP's membership has declined from its peak, and the party faces an uncertain future without Farage, a crowd-pleasing populist who helped propel UKIP from political fringe to influential power broker.
Farage said Monday he wouldn't be a "back-seat driver" to the new leader, and would retain his seat in the European Parliament until the term ends in 2019.
Farage's international profile has grown because of his strong relationship with Trump, who suggested in a tweet that Farage would make a good British ambassador in Washington.
The British government quickly replied that there was no vacancy for the job.
Farage said Monday he was heading to the U.S. this week — "purely as a tourist. Nothing more than that."