May and her team are adamant they would never have accepted different terms for different parts of the Union.
The DUP phone call likely resulted from them reading in the press and hearing on the air that it was accepted when it never was.
As David Davis said yesterday, no UK government would accept that.


"Sources in Brussels however said that though officials on both sides were in broad agreement over the solution to the problem, Downing Street has so far felt unable to sign off on it.
RTE says the draft deal said: ?In the absence of agreed solutions the UK will ensure that there continues to be no divergence from those rules of the internal market and the customs union which, now or in the future, support North South cooperation and the protection of the Good Friday Agreement.? "

"The PM has been clear that the UK is leaving the European Union as a whole and the territorial and economic integrity of the United Kingdom will be protected," the Prime Minister's spokesperson said.
Speaking at Stormont DUP leader Arlene Foster said: ?We note the speculation emanating from the European Union exit talks regarding the Republic of Ireland and United Kingdom border.
"We have been very clear. Northern Ireland must leave the EU on the same terms as the rest of the United Kingdom. We will not accept any form of regulatory divergence which separates Northern Ireland economically or politically from the rest of the United Kingdom. The economic and constitutional integrity of the United Kingdom will not be compromised in any way.
"Her Majesty?s Government understands the DUP position.? The Prime Minister has told the House of Commons that there will be no border in the Irish Sea. The Prime Minister has been clear that the UK is leaving the European Union as a whole and the territorial and economic integrity of the United Kingdom will be protected.
"We want to see a sensible Brexit where the Common Travel Area is continued, we meet our financial obligations, have a strictly time limited implementation period and where the contribution of EU migrants to our economy is recognised in a practical manner.
"The Republic of Ireland claim to be guarantors of the Belfast Agreement but they are clearly seeking to unilaterally change the Belfast Agreement without our input or consent.?
https://www.belfasttelegraph.co.uk/news/northern-ireland/arlene-foster-says-dup-will-not-accept-brexit-divergence-which-separates-northern-ireland-from-rest-of-uk-36377055.html