UK and EU edge closer to trade war over Northern Ireland

The warning comes after the UK government escalated the conflict over the Northern Ireland protocol — a set of post-Brexit trade rules — by saying it will unilaterally pass a law to change the trade treaty signed by the the EU and the UK two years ago.

London said the draft bill was an insurance policy in case it cannot reach agreement with Brussels to end a dispute over the protocol.

The commission made several proposals last October to cut red tape for businesses, but the UK has so far rejected those proposals. The EU has been unwilling to reopen the protocol, which the UK government previously negotiated, agreed and signed.

The protocol was put in place to avoid a border on the island of Ireland, between EU member the Republic of Ireland and non-EU Northern Ireland, and maintain the integrity of the EU's single market at the same time. Essentially a customs border has been moved to the Irish Sea, irking unionists in Northern Ireland.

UK prime minister Boris Johnson has said the UK's plans involve getting rid of "relatively minor barriers to trade".

Foreign secretary Liz Truss told MPs in the House of Commons that the planned legislation would ease the movement of goods, setting out a "green channel" for goods moving from Britain to Northern Ireland, and end the role of the European Court of Justice as the sole arbiter.

She said that the move "is consistent with our obligations in international law."

However, the EU has a different interpretation.

The EU has said that "unilateral actions contradicting an international agreement are not acceptable".

"Should the UK decide to move ahead with a bill dis-applying constitutive elements of the protocol as announced today by the UK government, the EU will need to respond with all measures at its disposal," Šefčovič said.

German centre-right MEP David McAllister, who chairs the European parliament's foreign affairs committee, said that unilateral action will only make finding a compromise more difficult.

"The EU takes a unified stance: we want sustainable solutions in the framework of the protocol. Renegotiations won't serve the purpose. The protocol is part of the solution, it is not the problem," he added in a tweet.

The British bill will only be published in the coming weeks, and could be used as a threat in negotiations by the UK to reach a compromise with the bloc.

"Our preference is to reach a negotiated outcome with the EU," Truss said.

In the meantime, in Northern Ireland, the Democratic Unionist Party is blocking the formation of a new power-sharing government in Belfast until the protocol is scrapped.

A government can only be formed with the cooperation of both biggest unionist and nationalist parties. But in recent elections, nationalist Sinn Fein emerged as the biggest party.