Theresa May has set Britain on course to leave the EU by 2019 in her first major speech on Brexit, saying that the UK would become a "fully independent, sovereign" country in the clearest sign yet that she wants a clean break from Europe's single market.
The prime minister told cheering Conservative supporters at the Tory party's annual conference that Britain would insist on taking full control of immigration and refuse to accept the jurisdiction of the European Court of Justice.
Although Mrs May's team denied she had decided to quit the single market, the EU sees the free movement of workers and oversight of a single court as indispensable pillars of a common market.
"She seems to be saying that regaining sovereignty is so valuable, she is willing to pay a price in terms of economic disruption," said one senior EU diplomat.
Mrs May said she wanted to give "British companies the maximum freedom to trade and operate in the single market", but not at the expense of allowing free movement or accepting the jurisdiction of judges in Luxembourg.
Meanwhile she told the conference that the UK would trigger Article 50, the official legal notification to its EU partners that it is going to leave the bloc, "no later than the end of March".
Once this formal process begins, Britain will have two years to hammer out a future relationship; Mrs May hopes to hold informal negotiations before the procedure formally begins.
There was relief in Brussels that Mrs May has committed to a Brexit timetable and that she has pledged to respect the EU's rules for leaving the union, but EU leaders have so far refused to contemplate "pre-negotiations" before Article 50 is activated.
Some diplomats in Brussels think that there will now be talks on the process of exit, which will inevitably touch on basic issues of substance.