FILE - In this Sunday, Nov. 10, 2019 file photo, former British Prime Ministers Tony Blair, left and John Major attend the Remembrance Sunday ceremony at the Cenotaph in Whitehall in London.
One major element of the Brexit withdrawal agreement is the section related to ensuring an open border on the island of Ireland to protect the peace process in Northern Ireland.
The issue proved thorny during the more than two years of discussions it took to get a Brexit deal done, as the border between Northern Ireland and Ireland is the only land link between the U.K. and the EU.
As a result, the two sides agreed there would be some kind of regulatory border between mainland Britain and Northern Ireland.
Major and Blair, who both vociferously opposed Brexit, said the planned legislation puts the 1998 Good Friday agreement that ended decades of violence in Northern Ireland at risk.