"They have demonstrated a total lack of any strategic appreciation of what they are doing".
Negotiators were dispatched for talks in Brussels on Friday, with reports suggesting their success paved the way for an entry into the "tunnel" phase of intensive and secretive discussions.
The accelerated negotiations were agreed to by the EU27 after a "constructive meeting" between the bloc's chief negotiator Michel Barnier and Brexit secretary Stephen Barclay in Brussels today.
This would be a major breakthrough and a cause for celebration in Ireland and certain parts of the UK- already the pound has risen significantly against the dollar - but Mr Johnson is set for huge backlash from the DUP if has indeed agreed for Northern Ireland to be treated differently to the rest of the UK. "It's important now that our negotiators on both sides get into proper talks about how to sort this thing out".
Meanwhile, Tusk said that on Friday morning that he had received "promising signals" from Irish prime minister Leo Varadkar, who met with Boris Johnson on Thursday.
There has been speculation that Johnson could now try to revive a compromise proposal first put forward by Theresa May that would see Northern Ireland remain politically in a customs union with the EU, but that it would be administered by the UK.
THERE was growing optimism about the prospect of securing a Brexit deal last night after the DUP appeared open to accepting the revised proposals that emerged after Thursday's meeting between the taoiseach and the British prime minister.
Sinn Fein president Mary Lou McDonald said: "Negotiations are at a very sensitive point".
However, we are yet to see concrete details on the deal. The next week will be critical.
"No veto can be given to unionism on protections for Ireland".
Just two days before Thursday's breakthrough, Johnson's advisors said that brokering a compromise was "essentially impossible" following a hard meeting with German Chancellor Angela Merkel.
"Both governments and the European Union negotiators need space to work out the detail and we'll wait to see that detail before coming to a judgment".
"The EU strongly objected to a proposal in Johnson's Brexit blueprint for Northern Ireland to leave the customs union together with the rest of the United Kingdom â€" meaning the return of customs controls on the island of Ireland. No ifs, no buts.
"It is hard to be optimistic given the past few years, but Alliance is clear any withdrawal agreement must recognise the particular circumstances of Northern Ireland - ensuring open borders, protecting our economy and respecting the Good Friday Agreement fully", he said. "We would encourage others to be measured and not rush to judgement".
She said her party would continue to "exercise our considerable influence" over the British government and that support for any deal was conditional on it being in the north's "long-term economic and constitutional interests".
The PM has said that, while he will abide by the law, he is determined to leave on the Halloween deadline of October 31 come what may.