The European Council President has called on the UK Prime Minster to bring a "realistic suggestion" for moving the Brexit process forward when she arrives in Brussels tomorrow.

Donald Tusk was speaking after a meeting with the Taoiseach Leo Varadkar in Brussels this morning.

He again warned that the Brexit Withdrawal Agreement - including the Irish border backstop - is not open to re-negotiation.

He said the EU would not be "making any new offer" to the UK outside of the agreement. 

He said the Irish border remains the EUs top priority in the process.

"The EU is first and foremost a peace project,” he said. “We will not gamble with peace or put a sell-by date on reconciliation."

"This is why we insist on the backstop."

Mrs May will arrive in Brussels for Brexit talks tomorrow - before travelling to Dublin for talks with the Taoiseach on Friday.

Mr Tusk said the EU is continuing to plan for the “possible fiasco” of a no-deal Brexit.

He also lashed out at politicians who supported Brexit in the run-up to the 2016 referendum - without knowing what it would involve.

"A sense of responsibility also tells us to prepare for a possible fiasco," he said.

"The Taoiseach and I have spoken about the necessary actions in case of 'no deal.'

"By the way, I have been wondering what the special place in hell looks like for those who promoted Brexit without even a sketch of a plan of how to carry it out safely."  

I've been wondering what that special place in hell looks like, for those who promoted #Brexit, without even a sketch of a plan how to carry it out safely.

— Donald Tusk (@eucopresident) February 6, 2019

He said that if the UK could offer a "deliverable guarantee for peace in Northern Ireland," it would leave the EU as a "trusted friend."

"I hope that the UK Government will present ideas that will both respect this point of view and, at the same time, command a stable and clear majority in the House of Commons," he said.

"I strongly believe that a common solution is possible and I will do everything in my power to find it." 

The Taoiseach said the withdrawal agreement  is the "the best deal possible," noting that it was negotiated over many months and agreed by 28 Governments - including that of the UK.

"While we expect that the backstop will never be used, we agreed again today that it is needed as a legal guarantee to ensure that there is no return to hard border on the island of Ireland, while protecting the integrity of our European single Market and Customs union.

"I think the events in London and the instability in British politics in recent weeks demonstrates exactly why we need a legal guarantee and a solution that is operable - that we know will work and will last." 

He said the two leaders had agreed that protecting the hard-won peace and stability, civil rights and people's rights on the island of Ireland was a "fundamental EU issue, that we will stay united on."

"As the leader of a small country that is fully committed to the EU, this solidarity resonates deeply in Ireland - but not just in Ireland; in all small member states as well," he said. 

He said the EU was prepared to change the "content and level of ambition" in the political declaration that complements the agreement - if the UKs plans for its future relationship with the EU were to evolve.

He said this could only happen if the "established principles" contained in the agreement are respected.

He voiced his hope that the Withdrawal Agreement be ratified by both the UK and European Parliament, noting that "once that is done negotiations on the future relationship can start in earnest."

He said preparations for a 'no-deal' scenario must "continue and intensify" in the meantime.

Remain 

Mr Tusk said he would like the UK to remain in the EU - but noted that the Conservative Government is committed to leave and there is no effective leadership in the UK pushing for remain.

"People all over the continent, and in Ireland, hoped that the UK would change its mind about Brexit," he said.

"But the facts are unmistakable -  at the moment the pro-Brexit stance of the UK prime minister, and the leader of the opposition, rules out this question.

"Today there is no political force, and no effective leadership, for remain."