The European Council President revealed the bloc had come up with “new guidelines” to avoid a hard border on the island of Ireland which are acceptable to both London and Dublin.
Speaking at a press conference this afternoon, Mr Tusk said it would be up to Britain to iron out the finer points, but suggested an agreement on the border could be much closer than previously thought.
He said he had “some good news for Prime Minister May” and announced he had recommended to European Union leaders they accept the proposed transition terms drafted earlier this week.
The deal includes protection for EU citizens’ rights – a major sticking point in previous talks – but no solution on what to do with the Irish border, other than the stipulation that all options would be kept on the table.
This condition, dubbed the ‘December agreement’, included a promise by the UK that “full regulatory alignment” could be on the cards if no other way to avoid a hard border could be reached.
When asked why he would recommend transition terms that did not include a solution for the Northern Ireland border question, he said: “The Irish question remains our highest priority.
“I am in a permanent content with Taoiseach Varadkar and, trust me, our latest proposal when it comes to new guidelines is also acceptable for Dublin and for London.
“Still we need more time to clarify, it is the British obligation to clarify the logistic and legal details, but today I can say our interpretation of the so-called December agreement is almost identical compared to the British position.
“I am absolutely sure that we will finally find a proper solution to avoid this question of a hard border.”
“The Irish question remains our highest priority.”
UK and EU negotiators announced earlier this week they had reached an agreement on a “large part” of the transition terms which will effectively keep the UK inside the bloc as a silent partner until December 2020.
Brussels had insisted it would not budge from its transition demands.
However, the UK won a victory on the issue of trade, with the EU conceding Britain would be able to sign and seal international deals.
On citizens rights, however, the UK accepted it will provide the same rights and guarantees to EU citizens who arrived after Brexit day on March 29, 2019, but before the end of the transition.
Theresa May had previously insisted she would reject this demand, arguing those arriving during the transition would be doing so with the full knowledge Britain had already technically left the EU.
Express.co.uk contacted the Department for Exiting the European Union to ask whether officials in Britain were aware of any new proposals which would solve the Irish border issue.
A spokeswoman for the ministry said Brexit Secretary David Davis had already made the UK’s position on Northern Ireland and Ireland clear while announcing the transition breakthrough on Monday.
Mr Davis said both the UK and EU were committed to avoiding a hard border on the island of Ireland.
He also reiterated Britain’s commitment to so-called “backstop” measures if a solution cannot be reached.
This outcome would essentially see Northern Ireland mirror the EU rules and regulations in neighbouring Ireland to avoid the need for a hard border.