THE backstop does not affect the constitutional status of Northern Ireland or breach the Good Friday Agreement, according to the British Attorney General's legal advice on the proposed withdrawal agreement.
Attorney General Geoffrey Cox QC said Theresa May's deal does not affect the principle of consent, or the "essential state functions or territorial integrity of the United Kingdom".
The DUP has argued that the deal brokered last month threatens the integrity of the union but according to the attorney general's legal position, the north cannot cease to be part of the UK without the consent of a majority of its people.
Mr Cox's legal advice also states how the backstop – or protocol – would continue to apply "unless and until it is superseded" by a subsequent agreement.
The 43-page Legal Position On The Withdrawal Agreement, released yesterday afternoon, states that the protocol's main provisions come into force on December 31 2020, at the end of the implementation period and in the event that a subsequent agreement is not in place by then.
Read more:What does the Brexit withdrawal agreement say about the Irish border?
But if the implementation period is extended then the backstop will not apply until after the end of that period, the paper states.
The attorney general has also confirmed that neither the UK nor EU would be able to unilaterally end the backstop arrangement if it came into force.
The backstop was "expressly agreed not to be intended to establish a permanent relationship but to be temporary", and the Article 50 process did not provide a legal basis for a permanent arrangement, he said.
Read more:
- Leading economist David McWilliams says DUP needs 'prosperity, not Protestantism' to prevent united Ireland
- DUP on 'wrong side' of withdrawal agreement argument, says Michelle O'Neill
