After nearly a year of waffling, Britain on Monday finally opens negotiations with its European Union counterparts about leaving the bloc, with the final outcome, due in 2019, as important as it now seems unpredictable.
Chief U.K. negotiator David Davis and his European Union counterpart, former French foreign minister Michel Barnier, told reporters in Brussels that they would first address key questions over how much the U.K. owes the bloc, and the rights of millions of citizens who have settled in Britain or Europe.
Other issues on the agenda, at least in the near term, include establishing residential rights of more than 3 million European Union citizens now living in the United Kingdom - and the 1 million British expats living in European Union member states - once the formal exit is complete.
"There is more that unites us than divides us", Davis said, referring to the latest reported terror attack overnight in London and the loss of lives in forest fires in Portugal.
With Mrs May still hammering out the details of a post-election deal to stay in power with the support of a small Northern Irish party, there are fears of a disorderly exit that would weaken the West, imperil Britain's US$2.5 trillion (S$3.5 trillion) economy and undermine London's position as the only financial centre to rival NY.
Failure to strike a deal before Britain automatically leaves the bloc on March 29, 2019, risks inflicting sweeping tariffs and uncertainty on both economies.
The election, which May called hoping to bolster her majority in parliament to give her a stronger negotiating position in Brussels, has left the prime minister with barely enough seats to govern if it manages to strike a deal with the DUP. May says Britain will leave the EU's single market in goods and services and its tariff-free customs union, but nonetheless, somehow, wants "frictionless" free trade. EU leaders want May to lay off threats that she would walk out and leave a chaotic legal limbo for all Europeans.
It highlights deep divisions between the United Kingdom and the EU's approach to talks, especially on the sequencing of the negotiations, with the United Kingdom wanting to sort out the financial settlement in parallel with an agreement on future relations. "A much more constructive and responsible tone is needed", he wrote, adding that "no deal has never been a viable option".
Mr Davis had previously said not settling both elements simultaneously would be the row of the summer.
Davis was heartened by the spirit of the talks, during which the negotiators, both interested in mountaineering, exchanged a walking stick and a hiking book.
And Hammond described the divorce bill figures being bandied around in Brussels as "the most egregious pre-negotiation posturing".
UK Chancellor Philip Hammond warned that the "no-deal" option would be "a very, very bad outcome" and that May's "no deal is better than a bad deal" mantra now seemed long gone.