The European Parliament's lead negotiators for Brexit talks has warned that discussions with the UK must conclude ahead of MEP election in mid-2019.
Speaking after a meeting with UK Brexit secretary David Davis, Guy Verhofstadt said officials had just less than a year and a half to reach a deal if, as expected, Prime Minister Theresa May launches divorce proceedings in early 2017.
“I also underlined the fact that parliament needs to give its consent. That takes a few months so the window for negotiations in fact, if you look to it more in detail, is more or less 14-15 months, let's be honest," Verhofstadt said.
Verhofstadt, a former Belgian prime minister, will work alongside Michel Barnier, who will represent the European Commission in talks with the UK.
And Verhofstadt also took the chance to reiterate his argument that the UK should not be able to find a resolution which allows for both Single Market membership and reforms to the freedom of movement.
"It is impossible to find a solution that would destroy the so-called four freedoms," Verhofstadt said.
"These four freedoms are key, they are a basic element of the European Union: the freedom of movement of goods, services, capital and of people. We will certainly never accept whatever development where these four freedoms at put at risk," he said.
Davis separately described the meeting with Verhofstadt as "a good start to the exercise".
"My view is that we can get an outcome here which will be in the interests of the European, and the interests of Britain, and will meet the requirements of the referendum. All of those are possible, but that's what the negotiations are about," Davis told the BBC.