No deal between the EU and the UK can be reached by mid-December

Should the EU and the UK fail to reach a deal, there is simply no time left for European governments and the European Parliament to ratify any agreement before March 29.

This ‘hard Brexit’ would mean that World Trade Organisation rules apply, generally adding 8 per cent tariffs on most goods and services moving between the UK and Europe. According to planning papers already issued, the ramifications would be huge, with car manufacturers warning that 800,000 jobs could be at risk. Because the EU regulates flights, all air traffic between the UK and Europe could be grounded for weeks, while the Bank of England Governor Mark Carney warns that house prices across Britain would plummet by one-third. Generally, it would be political, economic and socially chaotic.

The upside is the UK would be free to pursue its own trade deals, free from oversight from Brussels.