There is a “special place in hell” for pro-Brexit campaigners who demanded Britain leave the EU without explaining how it should happen, Donald Tusk has said.

The European Council president launched the scathing attack as he accused anti-EU campaigners of pushing for Brexit “without even a sketch of a plan how to carry it out safely.”

Mr Tusk also dismissed suggestions that the EU could reopen negotiations over the controversial Northern Ireland backstop, dealing a blow to Theresa May‘s hopes of securing fresh concessions as she tries to get her exit deal through parliament.

Speaking in Brussels alongside Irish taoiseach Leo Varadkar, Mr Tusk said: “I’ve been wondering what a special place in hell looks like for people who promoted Brexit without even a sketch of a plan how to carry it out safely.”

He also tweeted the accusation moments later.

Ms May is hoping to persuade the EU to place a time-limit on the backstop or give the UK the right to exit the mechanism unilaterally - a key demand of Tory rebels – but Mr Tusk said there would be no “new offer” from Brussels.

He said: “The position of the EU27 is clear, as expressed in the documents agreed with the UK government – that is, the withdrawal agreement and the political declaration. The EU27 is not making any new offer.”

Police separate clashing Brexit protesters outside Parliament Show all 11 1 /11 Police separate clashing Brexit protesters outside Parliament Police separate clashing Brexit protesters outside Parliament Anti-Brexit protester Steve Bray (left) and a pro-Brexit protester argue as they demonstrate outside the Houses of Parliament Getty Images Police separate clashing Brexit protesters outside Parliament A pro-Brexit protester argues Getty Images Police separate clashing Brexit protesters outside Parliament Police surround the pro-Brexit protester after he confronted Steve Bray, a pro-European protester Getty Images Police separate clashing Brexit protesters outside Parliament A leave supporter is spoken to by a police officer as he argues with a remain supporter, Steve Bray, outside Parliament PA Police separate clashing Brexit protesters outside Parliament MPs in Parliament are to vote on Theresa May's Brexit deal next week after her December vote was called off in the face of a major defeat Getty Images Police separate clashing Brexit protesters outside Parliament A leave supporter is spoken to by a police officer PA Police separate clashing Brexit protesters outside Parliament Police look on as anti-Brexit protesters demonstrate outside the Houses of Parliament. Getty Images Police separate clashing Brexit protesters outside Parliament Police hold back a leave supporter PA Police separate clashing Brexit protesters outside Parliament A police officer speaks with anti-Brexit protester Steve Bray Getty Images Police separate clashing Brexit protesters outside Parliament Police surround a pro-Brexit protester after he confronted a pro-European protester Getty Images Police separate clashing Brexit protesters outside Parliament Conservative MP David Davies, wearing a gopro camera, speaks to anti-Brexit protester Steve Bray Getty Images

Insisting that the backstop was necessary to maintain peace in Northern Ireland, he added: “The top priority for us remains the issue of the border on the island of Ireland and the guarantee to maintain the peace process in accord with the Good Friday Agreement.

“There is no room for speculation here: the EU itself is first and foremost a peace project. We will not gamble with peace or put a sell-by date on reconciliation. This is why we insist on the backstop.”

Ms May has promised to put forward a fresh plan for maintaining an open border in Northern Ireland by next Wednesday, but Mr Tusk warned that any new proposals from the UK must be “believeable”.

He said: “Give us a believable guarantee for peace in Northern Ireland and the UK will leave the EU as a trusted friend.

“I hope the UK government will present ideas that will both respect this point of view and at the same time command a clear and stable majority in the House of Commons.”

His stance was echoed by Mr Varadkar, who said he was “open to further discussions” with the UK but that the current withdrawal agreement remained ”the best deal possible”.

He said: “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 a 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.”

After their joint press conference, microphones recorded Mr Varadkar joking to Mr Tusk: “They’ll give you terrible trouble in the British press.”

A laughing Mr Tusk replied: “Yes I know.”

The comments sparked a furious response from Brexiteers.

Andrea Leadsom, the leader of the Commons, said Mr Tusk has "no manners", telling the BBC: “I think that what he has said is pretty unacceptable and pretty disgraceful.

"I'm sure that when he reflects on it he may well wish he hadn't done it."

The DUP’s Sammy Wilson called Mr Tusk a ”devilish, trident-wielding, euro maniac”, adding: “Donald Tusk once again shows his contempt for the 17.4 million people who voted to escape the corruption of the EU and seek the paradise of a free and prosperous kingdom. This devilish euro maniac is doing his best to keep the United Kingdom bound by the chains of EU bureaucracy and control.”