Democratic Unionist leader Arlene Foster has said “substantial positive progress” has been made in the Brexit talks following negotiations with the prime minister throughout the night.

“Throughout this process our guiding principle has been to act in the national interest to ensure the constitutional and economic integrity of the United Kingdom is not compromised as we leave the European Union,” said Mrs. Foster in a statement issued this morning.

“As a consequence of the engagement between the Government and our team, substantial positive progress has been made on improving the text of Monday's original draft paper. Contained within the new text we now have clear commitments that: Northern Ireland will leave the European Union along with the rest of the United Kingdom, Northern Ireland will leave the single market and the customs union along with the rest of the United Kingdom. There will be no customs or trade border down the Irish Sea between Northern Ireland and the rest of the United Kingdom.

“Northern Ireland will not be separated constitutionally, politically, economically or regulatory from the rest of the United Kingdom and the joint UK-EU report at the conclusion of phase one makes clear that in all circumstances the United Kingdom will continue to ensure the same unfettered access for Northern Ireland’s businesses to the whole of the UK internal market. There will be no so called ‘special status’ for Northern Ireland as demanded by Sinn Fein.

“The report makes it clear that the UK remains committed to preserving the integrity of its internal market and Northern Ireland's place within it, as it leaves the EU's internal market and customs union,” she said.

The Fermanagh-south Tyrone MLA believes “there is still more work to be done to improve the paper.”

“Specifically, more work is needed around the areas of cooperation where it would be necessary to have alignment of rules and standards, how any alignment could be effected without staying in the single market and customs union and what necessary alignment may be required to happen.

“We do however welcome the assurance given by the prime minister and Brexit Secretary in Parliament that any alignment will be done on a UK wide basis, ensuring that there would be no barriers to trade between Northern Ireland and our most important market in the rest of the UK,” she said.

Mrs. Foster said the DUP “cautioned” the Mrs. May “about proceeding with this agreement in its present form given the issues which still need to be resolved and the views expressed to us by many of her own party colleagues.”

“We will play a full part with the Government in the second stage of the negotiations on a comprehensive trade deal. Nothing is agreed until everything is agreed and how we vote on the final deal will depend on its contents,” she said.