A row broke out over whether attempts should be made to persuade Britain to Remain in the EU as the heads of government met for European Council meeting in Brussels.

More seriously for the Brussels eurocrat attempts to bully Britain with a “unified” front from the other 27, furious infighting erupted over who should host the two EU agencies currently based in Britain.

An alleged attempt by France and Italy to stitch up the issue was met with anger from other member states.

As Theresa May arrived with a clear vision over what she hopes to achieve with Brexit, European Council President Donald Tusk opened up divisions in the EU with an attempt to open the door to keep Britain under Brussels rule.

Mr Tusk quoted John Lennon's Imagine at a press conference in Brussels, saying "you may say I'm a dreamer, but I'm not the only one" while addressing the prospect of the UK remaining in the bloc.

He said the European Union was "well prepared" for the "difficult" Brexit negotiations, which formally started in the Belgian capital on Monday.

Mr Tusk said: "The Brexit negotiations started three days ago. It is a most difficult process, for which the EU is well prepared.

"You can hear different predictions coming from different people about the possible outcome of these negotiations - hard Brexit, soft Brexit or no deal.

"Some of my British friends have even asked me whether Brexit could be reversed and whether I could imagine an outcome where the UK stays part of the EU.

"I told them that, in fact, the European Union was built on dreams that seemed impossible to achieve. So, who knows. You may say I'm a dreamer, but I'm not the only one."

He was backed up by new Irish Taoiseach Leo Varadkar, who is desperate for Britain to stay and said as he entered that summit that “the door remains open for the UK” to change its mind.

And French President Emmanuel Macron has also said Britain could stay.

But in a sign of growing tensions within the EU over the Brexit strategy, Belgian Prime Minister Charles Michel and German Chancellor Angela Merkel attempted to slap down Mr Tusk.

Indicating that he wants Britain to go, Mr Michel Tweeted: “It's time for action and certainty. Not for dreams and uncertainty #Brexit #FutureofEurope #EUCO”.

Meanwhile Mrs Merkel said: "I want to say clearly that for me designing the future for the 27 takes priority over the negotiations with Great Britain over withdrawal.

"Naturally we will conduct these negotiations quickly and we will conduct them intensively. We will do everything to ensure that - as has been successfully done so far - the 27 states stick together."

The legal position over whether the Article 50 process is reversible has not been resolved and would need to be tested in the courts.

However, the UK Government which triggered Article 50 before the election, maintains that it means Britain has to leave in two years unless an extension is agreed by other EU member states.

Mr Tusk’s cack handed attempt to keep Britain in the EU appears to be a reaction to so called “Remoaner” MPs such as Labour’s Chuka Umunna. Tory Anna Soubry and the Lib Dems with their wealthy backers, including Gina Miller and Richard Branson, who want to overturn the historic EU referendum with another vote.

Mr Tusk’s intervention comes as senior figures in Brussels begin to panic over how to fill the gap in their budget once Britain’s £10 billion net contribution is removed.

The attempts to undermine Britain’s Brexit negotiations comes as the unified front put on by the other 27 states began to crack with a row over which countries will host the EU agencies which will have to move their headquarters out of Britain after Brexit.

The European Medicines Agency and European Banking Authority will need new homes and there is no agreement over the rules of competition to decide their new homes.

A senior EU diplomat said: "If we fail to agree on even the rules of how to do this, then we fall at the first hurdle for our unity over Brexit.

“The Brits will be popping the champagne corks if we can't agree."