LONDON (Reuters) - The favourite to take over as leader of the anti-EU UK Independence Party said on Thursday he would seek to hold new Prime Minister Theresa May's feet to the fire to ensure she sticks to her promise of removing Britain from the bloc.
UKIP leader Nigel Farage, among Britain's most outspoken and effective anti-EU campaigners, said this month he would stand down after having realised his ambition of winning a June 23 referendum in which Britons voted to leave the European Union.
May, who took office on Wednesday, supported her predecessor David Cameron's campaign for Britain to remain in the bloc but has since stressed that "Brexit means Brexit".
Launching his leadership bid on Thursday, UKIP migration and financial affairs spokesman Steven Woolfe said the party would speak for the 17.4 million people who voted for Brexit.
"Our job, together, is to make sure this government and this new prime minister respect the wishes of the British people. Brexit must mean Brexit. Not some watered down version, no Brexit-lite, no side-stepping, no back-sliding," Woolfe said in a speech to party supporters in London.
"The British people voted to leave the European Union. The people voted for this United Kingdom to control its own money and to make its own laws and to control its own borders. What the British people voted for, the British people must get."
UKIP won 12.6 percent of the vote in last year's national election but under Britain's winner-takes-all system, it gained only one seat in parliament.
The Brexit vote pitched Britain into political crisis with both major parties thrown into leadership battles.
While the governing Conservatives quickly resolved theirs, the opposition Labour Party is due to hold a contest over the summer after embattled leader Jeremy Corbyn was challenged for the leadership by two of his lawmakers.
Woolfe appealed to "let-down" Labour voters and Conservative voters who he said had supported leaving the EU but had now been "lumbered with" May.
"UKIP will welcome you," he said. "Nigel Farage has given our party a huge opportunity to launch a new era in British politics. We in UKIP must take this chance. We must ruthlessly go after Labour seats in the north and the Midlands."