Jim Allister: The joint McGuinness-Foster letter to Theresa May set the scene for the backstop

Such, of course, would negate a one nation Brexit, tearing up the critical mantra that “we joined as one nation, and must leave as one nation.”

This is the principle on which all unionists have united.

It would be a shame to see it shredded.

The take off point for such a landing zone was the ill-conceived Foster/McGuinness letter to the prime minister of 10 August 2016.

That fateful letter started the ball rolling on all the nonsense of ‘special status’ for Northern Ireland and, ultimately, in Mrs May’s disastrous deal manifested itself in the backstop.

Now, it is the cloak for a ‘landing zone’ that would take us outside the boundaries of the much promised one nation Brexit.

The August 2016 letter was fateful in two regards.

Firstly, it spawned and gave DUP imprimatur to a border which was no “impediment to the movement of people (labour), goods and services” (the very essence of the EU single market from which Brexit should be delivering us), the retention of current trade patterns with the EU, the free flow of EU labour and special measures for agri-food involving the avoidance of tariffs (which suggests contentment with staying in the EU Customs Union).

None of this is compatible with a clean Brexit, but rather anticipates continuing ties to the EU acquis and controls, while GB breaks free.

Secondly, the letter itself is a vivid illustration of at least the fudge which would attend any Stormont pseudo oversight of EU rules.

With DUP and Sinn Fein pulling in opposite directions, the inevitable outcome would be, at best, a fudge, but more likely unionist climbdown as the price of keeping Stormont alive.

No unionist left to themselves would have drafted such a letter as that of August 2016, but, beholden to Sinn Fein, this was the product. It must not become the shackle that now binds us in perpetuity to the EU, in part or in whole.

Jim Allister QC MLA, TUV leader