Nigel Farage’s critics call him a "shameless opportunist.”

On Monday, the Brexit architect picked the perfect moment to deal Prime Minister Rishi Sunak a gut punch — the day before the first TV debate of the U.K. election campaign and just as a major poll put the prime minister’s ruling Conservatives on track for a historic rout.

With trademark chutzpah, Farage convened what he called an "emergency” press conference in London to tell reporters that he would, in fact, be standing as a candidate for his Reform U.K. party in the election — reversing a decision from less than two weeks ago that helping put Donald Trump back into the White House in the U.S. presidential election in the autumn was a better use of his time.