He said all 27 countries in the bloc would be in favour if a new government decided to reverse the Article 50 process.

He said in an interview with the Guardian: “If the UK, after the election, wants to withdraw (Article 50), then the procedure is very clear.

“If the UK wanted to stay, everybody would be in favour. I would be very happy.”

Meanwhile, the European Commission’s draft negotiating document indicated that Brussels officials believe that the ECJ should rule over any agreement on citizens’ rights.

Mr Tajani said: “Under the (Brexit) treaty everything under the treaty is under the court.”