Reports from Brussels claim the Prime Minister is bringing back a proposal first put forward by Theresa May for a customs partnership between the UK and the bloc. The make-or-break compromise would see Northern Ireland remain politically in a customs union with the EU but it would be administered by the UK.
But the DUP’s deputy leader Nigel Dodds insisted the last-ditch plan “cannot work”.
Mr Dodds told Italian newspaper La Repubblica that Northern Ireland “must stay in a full UK customs union, full stop”.
He said: “It cannot work because Northern Ireland has to remain fully part of the UK customs union.
Businesses would then be able to claim a rebate once they had shown the goods were for consumption in the UK market.
The compromise would mean that Northern Ireland would be able to benefit from any post-Brexit trade deals the UK strikes in a major win for Mr Johnson.
The Prime Minister has so far refused to say if he has backed down over the Irish border issue.
Speaking during a school visit on Friday, Mr Johnson insisted he would not accept anything that “damages the ability of the whole of the UK to take full advantage of Brexit”.
It comes after an apparent Brexit breakthrough on Thursday when the Prime Minister held crunch talks with his Irish counterpart Leo Varadkar.
But Mr Johnson warned it was not a “done deal” and there was still “a way to go” to reach an agreement for the UK to leave the bloc on the October 31 deadline.