The Single Market Act passed a law on Tuesday giving ministers the power to break their divorce treaty with the European Union, despite the threat of legal unrest within the Tory party in Brussels.
The British Single Market Act, recognized by ministers as a violation of international law, was passed by 340 votes to 256 and is now going to the House of Lords for debate.
The law is designed to protect free trade between the four British nations after a Brexit transition period has expired, but has tainted relations with Brussels just as time runs out to reach an agreement on their long-term relationships.
After an initial turmoil within Prime Minister Boris Johnson's party, including criticism from three former Conservative Prime Ministers, a concession to give parliament a say in the use of powers erased a rebellion.
The government says clauses in the bill overriding the readmission agreement that Johnson signed in January are necessary to protect free trade with Northern Ireland and will only be used if talks on a border solution with the EU fail.
The EU, which wants to ensure that Northern Ireland's open border with the Irish Member State does not act as a back door for goods to enter the bloc, is an extremely serious breach of the exit treaty and threatens to sue.
The examination in the House of Lords, the upper chamber of Parliament, is expected to last until early December. Johnson does not have a majority there and revisions of the most controversial clauses should find strong support.
However, talks with the EU are expected to move faster and if an agreement on an Irish border solution can be reached the powers may not be needed.
If there is no agreement, any changes made by the Lords would have to be approved by the Commons, creating the potential for a political stalemate.