Ballots closed in the race to become Britain's next prime minister on Monday, with the favorite Boris Johnson facing more defections by ministers over his Brexit plan. The country's new leader will take the reins this week and have just three months to attempt to resolve a three-year Brexit crisis that could damage economies on both sides of the Channel and determine the fate of generations of Britons.
The month-long contest between former London mayor Johnson and Foreign Secretary Jeremy Hunt is being decided by fewer than 200,000 grassroots members of the governing Conservative Party.
The new party leader will be announced on Tuesday and take over as prime minister on Wednesday.
Both candidates have had a rocky end to a campaign whose closing stages are being waged against a backdrop of a high-stakes stand-off with Iran in the Gulf.
Finance minister Philip Hammond announced on Sunday that he would make a point of resigning before Johnson becomes prime minister due to his threat to take Britain out of the EU by an Oct 31 deadline without a deal if one cannot be agreed with Brussels.
London newspapers were filled with speculation that at least a half-dozen lower-ranking ministers may also jump ship over the coming days.
But Johnson doubled down on his pledge to take Britain safely out of the European Union with the help of a new unspecified technological fix for avoiding a hard border with EU member Ireland.
They went to the Moon 50 years ago. Surely today we can solve the logistical issues of the Irish border, Johnson wrote in his weekly column for The Daily Telegraph newspaper.
Hunt has also faced criticism over his handling of Iran's seizure of a British-flagged tanker in the Gulf on Friday.
Several ministers accused him on Sunday of devoting too much time to his leadership campaign and not enough on his diplomatic duties.
An online poll of 1,199 Conservative Party members conducted on Friday and Saturday by the Conservative Home website put Johnson on 73%.
Bookmakers give Hunt around a one in 20 chance of winning.
The Conservatives command a razor-thin majority in parliament's lower House of Commons and Johnson's opponents - both within and outside the party - are keen to scupper his leadership.
Johnson's pledge to take Britain out of the EU with our without a deal has upset pro-EU government ministers and frightened the markets.
The pound is trading near a two-year low against the dollar and the euro, and parliamentarians are looking for ways to stop Johnson from taking Britain out of the EU without a strategy for unwinding 46 years of intricate ties.
Conservatives MPs like Hammond have hinted they are prepared to bring down their own government rather than leave the EU without an agreement.
I cannot accept the idea of leaving with no deal on October 31, Hammond said on Sunday.
Justice Secretary David Gauke also said on Sunday he would quit the government if Johnson became prime minister.
May's tumultuous three years in office will end after she appears in parliament on Wednesday for her weekly question-and-answer sessions.
She will give a speech in front of her Downing Street residence and head from there to Buckingham Palace to tender her resignation to Queen Elizabeth II.
The head of state will then invite the new Conservative leader to form an administration.