LONDON — The British authorities served discover on Tuesday that it might unilaterally scrap a few of the rules that govern commerce with Northern Eire, a extremely political transfer that units Britain on a collision course with the European Union, 18 months after a commerce deal that was meant to have doused the final fires of Brexit.

The overseas secretary, Liz Truss, mentioned {that a} proposed new regulation would enable the British authorities to regulate guidelines on commerce between mainland Britain and Northern Eire, which had been painstakingly negotiated in an settlement with Brussels.

“To reply to the very grave and severe state of affairs in Northern Eire, we’re clear there’s a necessity to behave,” Ms. Truss mentioned in Parliament. “We have to restore the steadiness within the settlement.”

Ms. Truss insisted that she wished to alter reasonably than scrap the settlement governing post-Brexit commerce, generally known as the Northern Eire protocol. She additionally mentioned that the problems it addresses may very well be resolved in negotiations with the European Union reasonably than with unilateral motion.

However, if enacted, such a regulation might rip up a part of the commerce cope with the European Union, establishing a brand new “inexperienced channel” that will take away checks on most items flowing from Britain to Northern Eire.

These checks had been agreed upon to keep away from disrupting commerce between Northern Eire, which is a member of the UK, and neighboring Eire, which is a part of the European Union, as soon as Britain left the bloc.

In her assertion, Ms. Truss mentioned the protocol had disrupted commerce between mainland Britain and Northern Eire. It’s opposed by the territory’s unionist events, which favor protecting Northern Eire as a part of the UK, and complain that the principles drive a wedge between the North and mainland Britain.

“Some companies have stopped commerce altogether,” Ms. Truss mentioned. “These sensible issues have contributed to the sense that the east-west relationship has been undermined.”

The announcement generates a number of dangers for the federal government of Prime Minister Boris Johnson: a possible commerce warfare with the European Union, rising tensions with the US, a doable rift within the Western alliance in help of Ukraine, and an unsure impression on the politics of Northern Eire itself.

Of those, a collision with Brussels can be by far probably the most severe, particularly at a time when the British economic system is struggling the hovering inflation that has bothered different nations due to provide shocks in meals and gasoline.

The governor of the Financial institution of England, Andrew Bailey, warned on Monday of an “apocalyptic” rise in meals costs due to shortages in wheat and different crops because of the warfare in Ukraine. The central financial institution, he mentioned, was “helpless” within the face of worth rises, with inflation projected to hit double digits by year-end.

If the European Union imposed retaliatory tariffs on items coming from Britain — a significant “if” — it will connect one other dragging anchor to an economic system that some analysts concern is already susceptible to tipping right into a recession. The mix of financial stagnation and surging costs has fanned fears of a return to the darkish days of the Nineteen Seventies.

Then, too, there may be the danger of upsetting relations with the Biden administration and Eire’s defenders on Capitol Hill. The White Home has warned Mr. Johnson to not do something that will jeopardize the Good Friday Settlement, the 1998 pact that ended a long time of sectarian violence within the North.

Richard Neal, the highly effective chairman of the Home Methods and Means Committee, mentioned that any laws that unilaterally abrogated parts of the protocol would undermine efforts to barter the commerce guidelines “at an especially fragile time.” He prompt that Britain’s transfer was pushed by politics.

“Northern Eire shouldn’t be held hostage within the political course of,” Mr. Neal mentioned in a press release. “Quite all events should keep the course and proceed to work collectively to seek out sturdy options.”

Ms. Truss didn’t publish her proposed new laws, the beginning of a protracted legislative course of to make it regulation, and British officers say that they hope talks with the European Union can proceed in parallel, probably making certain that the legal guidelines are by no means used.

The deliberate regulation would give the British authorities unilateral powers over tax and subsidy coverage in Northern Eire. Nonetheless it remained unclear to what extent the laws might take away or restrict the function of Europe’s high courtroom, the European Courtroom of Justice, in adjudicating commerce disputes.

Doing so can be seen by the European Union as a basic change to the protocol, reasonably than the form of sensible repair over border checks that it’s keen to ponder.