The UK government's bid to scrap parts of post-Brexit trade arrangements in Northern Ireland cleared its first hurdle on Monday, despite EU warnings it is illegal and could spark a trade war.
MPs in the House of Commons voted through the controversial Northern Ireland Protocol Bill by 295 votes to 221 after a debate, allowing it to progress to the next stage of scrutiny in parliament.
Prime Minister Boris Johnson, in Germany for a G7 leaders meeting, earlier insisted the legislation was needed to remove "unnecessary barriers to trade from Great Britain to Northern Ireland.
"All we're saying is that you can get rid of those, whilst not in any way endangering the EU single market," he told reporters.
MPs voted as Johnson socialised at the G7 with top EU leaders, including European Commission chief Ursula von der Leyen, German Chancellor Olaf Scholz and French President Emmanuel Macron.
Irish premier Micheal Martin rejected Johnson's attempts to play down the planned changes to the protocol, which was agreed as part of the UK's Brexit withdrawal from the European Union.
Martin said "any unilateral decision to breach international law is a major, serious development.
"There can be no getting out of that," he said in Dublin, also warning against another government bill to revamp human rights in the UK that could affect a 1998 peace deal for Northern Ireland.
In parliament, Johnson's predecessor as prime minister Theresa May, who quit after failing to get parliamentary backing for her own Brexit divorce deal, said she could not back the bill.
It was "not legal... will not achieve its aims and... will diminish the standing of the United Kingdom in the eyes of the world", she told MPs.
The UK government unveiled its plan to unilaterally change trading terms for the politically fraught British province earlier this month, prompting the EU to pledge legal action.
Brussels says overriding the deal it struck in 2019 with Johnson's government breaches international law, and has warned of trade reprisals, which Britain can ill-afford as prices surge on the back of the war in Ukraine.
Days of further scrutiny and subsequent votes now loom, and despite winning the vote, Johnson is facing criticism among some of his own Conservatives after he only narrowly survived a no-confidence vote this month.
Launching the debate, Foreign Secretary Liz Truss said problems were "baked in" to the protocol and wholesale change was needed to entice pro-UK unionists back to a power-sharing government in Belfast.
"It is both legal and necessary," she said, denying the UK was breaching international law and stressing the need to prioritise the peace process.
"We continue to raise the issues of concern with our European partners, but we simply cannot allow the situation to drift," Truss added.
There was no immediate response from Brussels.
But on Sunday, the bloc's ambassador to Britain, Joao Vale de Almeida, said the legislation did break international, EU and UK law, and was "unrealistic".
"We are committed to find the practical solutions on implementation, but we cannot start talking if the baseline is to say everything we have agreed before is to be put aside," he added.
The protocol requires checks on goods arriving into Northern Ireland from England, Scotland and Wales, to track products that could be potentially headed to the bloc via the Republic of Ireland.
This creates a customs border down the Irish Sea, keeping Northern Ireland in the EU's customs orbit to avoid a politically sensitive hard border between the territory and EU member Ireland.
Unionist parties and the UK government argue the protocol is threatening the 1998 Good Friday Agreement that ended three decades of violence over British rule in Northern Ireland.
They want checks to be removed on goods, and animal and plant products, travelling from Great Britain through the creation of a "green channel" for goods intended to stay in Northern Ireland.
