The UK's split from the EU should be delivered before 2019 to make way for the next round of elections in the European Parliament, top EU negotiator Guy Verhofstadt has argued. The senior MEP and former prime minister of Belgium, who is leading Brexit negotiations for the European Parliament, also warned that the UK cannot have what EU chiefs have dubbed as "single market a la carte".

"If [the] UK wants access to the single market, it must also accept the free movement of citizens. Our four freedoms are inseparable," Verhofstadt said.

But Prime Minister Theresa May has ruled out triggering Article 50 of the Lisbon Treaty, the official mechanism to split from Brussels, this year.

The government are expected to make the move in 2017, followed by two years' worth of negotiations with the EU. The so-called Brexit Department, a ministry set-up by May in reaction to the Leave vote at the referendum, will lead the government's negotiation efforts.

David Davis, a Leave campaigner and former Europe minister, heads up the Exiting the European Union department, with Liam Fox leading the Department for International Trade.

Liberal Democrat MP Tom Brake has warned that it could cost taxpayers' £750,000 a year for a top Brexit negotiator. "According to a headhunter I was speaking to a couple of weeks ago, the head of a trade negotiating team if hired as a consultant would cost around £750,000 a year," Brake told MPs.

Fox, meanwhile, hit the headlines over the weekend for reportedly suggesting that British business bosses were "fat and lazy" and would rather play golf than export goods and services.

The Eurosceptic made the comments during a speech to the right-wing Conservative Way Forward group, The Times reported. "[Fox] would do us all a favour if he thought before coming out with ridiculous generalisations," said Chuka Umunna, Labour's former shadow business secretary.

Read more: Who is Guy Verhofstadt?