The EU’s chief negotiator told London to strike a deal securing continued access to the European Union’s single market or the customs union.
If the British government was to opt for a so-called hard Brexit, severing all the current ties with Brussels, companies would face disruption to their supply chains.
Mr Barnier told the German Sunday newspaper Frankfurter Allgemeine Sonntagszeitung newspaper: “Should the British government decide in favour of a customs union with us, which is still possible, things would be much easier.”
The Frenchman’s warning comes after the European Union urged its member states to ramp up their preparations for a no-deal Brexit.
Should the British government decide in favour of a customs union with us, which is still possible, things would be much easier
Earlier this week, Mr Barnier said: "Brexit is not a game, it is far too serious.
"Our responsibility, including the business world, the unions, the citizens, the governments, is to be prepared for all options, this also includes a no deal scenario."
The EU negotiator warned again in his latest remark about the importance to be ready