If it is passed into law, the UK government could change the operation and oversight of the Brexit deal.
Image source, PA MediaThe Northern Ireland Protocol Bill moves to its next stage in the House of Lords on Tuesday.
Peers are scheduled to spend four days on line-by-line scrutiny of the proposed legislation.
The protocol is the Brexit agreement for Northern Ireland which was agreed by the UK and EU in 2019.
If the bill is passed into law it would give the UK government unilateral powers to change the operation and oversight of the protocol.
The UK has acknowledged this would breach the terms of the deal but has claimed this can be justified on the grounds of “necessity” under international law.
If it becomes law the EU could start fresh infringement proceedings under EU law or trigger the dispute resolution mechanism under the Brexit Withdrawal Agreement.
The protocol keeps Northern Ireland in the EU’s single market for goods, avoiding the need for a hard border with the Irish Republic after Brexit.
However, it also creates a new trade border between Northern Ireland and the rest of the UK, something the EU accepts is causing difficulties for many businesses.
Unionists also say it is undermining Northern Ireland’s place in the UK and is contrary to the spirit of the 1998 Good Friday Agreement, the peace deal which set up power sharing in Northern Ireland.
The Democratic Unionist Party (DUP) is refusing to return to power sharing at Stormont due to its opposition to the protocol.
The EU has proposed ways of easing the impacts of the protocol but the UK says these measures do not go far enough.
The UK government presented the protocol bill to the House of Commons in June and it was passed without amendment by the end of July.
It is expected to face a more difficult time in the Lords.
Peers have submitted more than 20 pages of amendments, including a Labour amendment which would require the government to “exhaust legal routes under the EU withdrawal agreement” before availing itself of the powers in the bill.