PRESSURE is piling on Theresa May to produce a clear Brexit plan as Ireland’s Leo Varadkar suggested Britain should have come up with one two years ago – before the EU referendum.

As the Prime Minister emphasised how both the UK Government and the EU27 wanted to go at a “faster pace” in the talks, the Irish Taoiseach accepted it was a possibility that the UK could "crash out" of the European customs union and single market without an agreement given time was running out.

Mark Rutte, the Dutch premier, noted: "I am not losing patience but time is getting shorter and shorter to come to an agreement."

Referring to the splits within Mrs May's Cabinet, he said: "I do understand it is difficult to come to an agreement within her Cabinet and the UK Parliament but she has to."

Jean-Claude Juncker, the European Commission President, said: "I don't have to lecture Theresa May but I would like our British friends to make clear their positions."

Asked if there was a risk there may not be a Brexit deal, he replied: "We are preparing for different scenarios on the proper withdrawal agreement but, in parallel, we are working on the no deal."

Ahead of dinner in the Belgian capital, which was suggested could last into the wee small hours of Friday, the PM struck an upbeat tone: "We've already seen and been able to encourage and get flexibility from the European Union on matters…

“Because this isn't just about the United Kingdom, it's about ensuring that we have a partnership that works for us and a partnership that works for us will work for the EU as well."

Next week, Mrs May at a Chequers away-day is expected to try to urge her Cabinet colleagues to agree to a White Paper that aligns Britain closely with the single market and customs union for goods but less so for services so that the economic risks of quitting the EU are minimised.

On the margins of the European Council, she had talks with Mr Varadkar, who made clear it would have been helpful if the UK Government had published a Brexit White Paper in 2016.

"You would have thought that before people voted to leave the European Union, they would have an idea what the new relationship would look like but I appreciate that that hasn't happened and two years later it still hasn't happened."

The Taoiseach urged Britain to soften its negotiating red lines and show some flexibility.

"It needs to understand that we're a union of 27 member states, 500 million people. We have laws and rules and principles and they can't be changed for any one country, even a great country like Britain.

"Any relationship that exists in the future between the EU and the UK isn't going to be one of absolute equals: we're 27 member states, the UK is one country, we're 500 million people, the UK is 60 million. That basic fact has to be realised and understood,” declared Mr Varadkar.

A leaders’ "Brexit breakfast" was scheduled for Friday morning as the main subject of the summit was migration.

Donald Tusk, the European Council President, in a letter to EU leaders ahead of the summit, proposed the creation of "regional disembarkation platforms" outside the bloc where migrants could be processed, separating refugees from economic migrants.

He warned: "There are voices in Europe and around the world claiming that our inefficiency in maintaining the external border is an inherent feature of the European Union, or - more broadly - of liberal democracy."

Before leaders gathered in Brussels, the embattled German Chancellor Angela Merkel starkly warned migration “could determine the fate of the European Union"; some observers suggested it was more likely to determine her own fate as leader of her country.

*The Commons Brexit Committee has recommended MPs should spend at least five days debating the final Brexit deal, saying how it would be "the most significant parliamentary debate in a generation".