The Secretary of State has triggered the process to enable MLAs to vote on the controversial post-Brexit trading arrangements.
Hilary Benn has sent a letter to the Stormont speaker and first and deputy first ministers urging them to bring forward a motion to the assembly before the end of November.
The process, known as the democratic consent motion, was first agreed between the UK and EU in the 2020 Withdrawal Agreement to give local politicians a say in the new post-Brexit trading rules
It allows MLAs at Stormont to decide if the current arrangements including the Northern Ireland protocol should continue.
Under the agreement the process has to be set in motion two months before the current arrangements are due to expire at the end of the year.
If the first and deputy first ministers fail to bring forward the motion to allow for the vote then an individual MLA can trigger the mechanism.
But controversially unlike other votes at Stormont there is no requirement for cross community support for the motion. A simple majority will suffice.
Sinn Fein, Alliance and SDLP are all expected to support the continuation of the arrangements.
But, the DUP has argued the vote creates a democratic deficit as the concerns of unionists who are in the minority at Stormont can be ignored.
If the vote is carried without cross community support then the government has committed to ordering an independent review of the post Brexit arrangements and their implications.
Analysis: ‘Expect a divided vote’
It will be one of the most significant and yet predictable votes in the Stormont chamber.
Whenever it happens MLAs will back the continuation of the post Brexit arrangements for another four years.
That is because unionists who are opposed to the arrangements are in the minority.
By way of compensation for them the government has promised to carry out an independent review into how the new trading rules are operating.
The government may also seek to ease the post Brexit burden in Northern Ireland through new agreements with the EU.
Whatever happens, expect a divided chamber and divisive vote.