By William James
BIRMINGHAM, England (Reuters) - The leader of Britain's anti-European Union UK Independence Party, Diane James, has resigned after only 18 days, throwing the populist party into turmoil only three months after it was on the winning side of the Brexit vote.
Although the June 23 vote represented success in UKIP's 25-year quest to see Britain leave the EU, it also triggered the resignation of its leader Nigel Farage and an existential crisis about what its new long-term mission should be.
James, a member of the European Parliament, had won a leadership contest on Sept. 16, promising to professionalize the party and use its political muscle to ensure the Conservative government did not negotiate a watered-down exit deal.
Inheriting a party riven with factional infighting and missing its former leader, James had said she would prioritize party unity and modernize its internal structure.
Less than three weeks into her reign, and before the party had even registered her officially as leader, she said late on Tuesday that aim had become impossible.
"I will not be formalizing my recent nomination to become the new leader of the party", she said in a statement posted on her Twitter account.
"It has become clear I do not have sufficient authority, nor the full support of all my MEP colleagues and party officers to implement changes I believe necessary and upon which I based my campaign."
On the sidelines on the party's annual conference in September, party officials and members had expressed concern that James, 56, lacked the same kind of popular appeal that had made Farage, a champion of Britain's 'anti-establishment' backlash, one of the country's most widely recognized politicians.
Farage ruled out a return and said he hoped some of UKIP's better known figures would run for the leadership this time around and that he expected they would.
"I'm sorry that what's happened today has happened but I will say this - it is better that it happened now than in six months' time," he told Sky TV.
The previous leadership contest had been marred by a decision to exclude one of the top candidates, Steven Woolfe, because he had submitted his nomination minutes after the deadline.
At the time, Woolfe described that decision as a 'coup' and criticized the party's National Executive Committee - the powerful internal body which James herself had pledged to reform.
(Additional reporting by Michael Holden in London and Ismail Shakil in Bengaluru; editing by Stephen Addison)