LONDON (AP) -- Prime Minister Boris Johnson on Monday renewed British threats to break a Brexit agreement with the European Union, blaming it for a political crisis that's blocking the formation of a new government in Northern Ireland.
Ahead of a visit to Belfast, Johnson said there would be "a necessity to act" if the EU doesn't agree to overhaul post-Brexit trade rules that he says are destabilizing Northern Ireland's delicate political balance.
Voters in Northern Ireland elected a new Assembly this month, in a vote that saw Irish nationalist party Sinn Fein win the most seats. It was the first time a party that seeks union with the Republic of Ireland has won an election in the bastion of Protestant unionist power.
The Democratic Unionist Party came second and is refusing to form a government, or even allow the assembly to sit, until Johnson's government scraps post-Brexit checks on goods entering Northern Ireland from the rest of the U.K.
Under power-sharing rules set up as part of Northern Ireland's peace process, a government can't be formed without the cooperation of both nationalist and unionist parties
Johnson was due to meet party leaders in Belfast, and urged them to get back to work and "focus on everyday issues. Schools. Hospitals. Cost of Living."
But he also accused the EU of refusing to give ground over post-Brexit border checks.
Northern Ireland is the only part of the U.K. that shares a border with the EU. When Britain left the bloc in 2020, a deal was agreed to keep the Irish land border free of customs posts and other checks, because an open border is a key pillar of the peace process that ended decades of violence in Northern Ireland. Instead, there are checks on some goods, such as meat and eggs, entering Northern Ireland from the rest of the U.K.
The arrangement is opposed by unionists in Northern Ireland, who say the new checks have put a burden on businesses and frayed the bonds between Northern Ireland and the rest of the U.K.
The British government agrees that the regulations, known as the Northern Ireland Protocol, are destabilizing a peace agreement that relies on support from both Protestant unionist and Catholic nationalist communities.
While the DUP wants the Protocol scrapped, most other parties in Northern Ireland want to keep it, with changes.
"There is no disguising the fact that the delicate balance created (by the peace agreement) in 1998 has been upset," Johnson wrote. "One part of the political community in Northern Ireland feels like its aspirations and identity are threatened by the working of the Protocol."
In the Belfast Telegraph, Johnson accused the EU of failing to recognize that the arrangements weren't working. He said the government wanted to change, but not scrap, the agreement.
"I hope the EU's position changes. If it does not, there will be a necessity to act," he wrote.
Johnson said his government would "set out a more detailed assessment and next steps to Parliament in the coming days." That's likely to be legislation that would give Britain powers to override parts of the Brexit treaty.
Any such bill would take months to pass through Parliament, but the unilateral move would anger the EU, which would hit back with legal action -- and potentially trade sanctions. The 27-nation bloc is Britain's biggest economic partner.
Ivan Rogers, a former British ambassador to the EU, said "I think there's a severe risk that we are heading into a trade war."
Irish Foreign Minister Simon Coveney said a U.K.-EU feud "is the last thing Europe needs right now, when we are working so well together in the face of Russian aggression and responding to the support needed for Ukraine at this time."
"This is a time for calmness, it's a time for dialogue, it's a time for compromise and partnership between the EU and the U.K. to solve these outstanding issues," he said in Brussels.