Prospects of a trade deal between Britain and the European Union appeared to dim on Wednesday, with the EU saying that even the smallest UK breach of the Brexit withdrawal treaty would undermine what little trust is left between the two sides.

The warning came as Britain pushed ahead with legislation that it admits breaks international law by overriding parts of the legally binding withdrawal agreement that both Britain and the EU signed up to.

“Breaking international law is not acceptable and does not create the confidence we need to build our future relationship,’” EU Council President Charles Michel said.

European Commission President Ursula von der Leyen said the age-old diplomatic cornerstone of “agreements must be kept” was “the foundation of prosperous future relations.”

Germany hoped Britain would pull back from the brink, but France, the bloc’s other economic and political powerhouse, was scathing.

French government spokesman Gabriel Attal said that “we are ready to negotiate in good faith, but to do that, we need to be two and so we are waiting for an interlocutor of good faith.”

Britain left the political structures of the EU on Jan. 31 and will make an economic break when an 11-month transition period ends on Dec. 31. The two sides are trying to strike a new trade deal by then, but talks have bogged down.

The UK government says its Internal Market Bill is a “safety net” designed to prevent disruption to internal UK trade in the event that there is no agreement by the end of the year.

The withdrawal agreement includes measures to ensure there are no barriers to trade or travel between Northern Ireland, which is part of the UK, and EU member Ireland. To do that, Britain has agreed that Northern Ireland will continue to follow some EU rules even after the rest of the UK goes it is own way. That means there will be checks and tariffs on some goods moving between Northern Ireland and the rest of the UK, with Britain and the EU jointly deciding what goods they apply to.

The UK legislation, if passed by Parliament, will remove the EU’s power to impose checks and tariffs in the event that there is no EU-UK-agreement, giving that power instead to the British government.

The British government says trade barriers between Northern Ireland and the rest of the UK could undermine Northern Ireland’s place within the UK and destabilize the peace settlement that ended decades of violence.

Johnson told lawmakers on Wednesday that the legislation was needed to protect against “extreme or irrational interpretations of the (Irish) protocol that could lead to a border down the Irish Sea.”

Critics say reneging on a legally binding international commitment will trash Britain’s reputation for upholding law and order.

Opposition parties and EU officials were astonished when Northern Ireland Secretary Brandon Lewis acknowledged in Parliament on Tuesday that the legislation “does break international law in a very specific and limited way.”

“The withdrawal agreement is not open for renegotiation and that we expect that the letter and the spirit of the withdrawal agreement will be fully respected,” European Commission Vice President Maros Sefcovic said.

Sefcovic said he was seeking an urgent meeting of the joint EU-UK committee on the Brexit Withdrawal Agreement. The UK government said it welcomed such a meeting.

Some members of Johnson’s Conservative Party are uneasy, too. Lawmaker Tobias Ellwood, who chairs the House of Commons Defense Committee, said that “to unilaterally ignore any treaty in its obligations which we’ve signed and submitted to the United Nations would actually go against everything we believe in.”

Britain’s move threatens to scuttle already deadlocked talks on a free trade deal between Britain and the bloc.

EU and UK trade negotiators are meeting in London this week, with both sides gloomy about a breakthrough on the key differences: competition rules and fishing rights. Johnson has said Britain will walk away if there is no agreement by Oct. 15.

Johnson says the UK wants a deal but insists a no-deal exit would be “a good outcome,” even though it would see tariffs and other impediments slapped on trade with the EU, which accounts for almost half of the UK’s total trade.

Without a deal, British freight firms have warned there could be logjams at ports and supplies of key goods in Britain could be severely disrupted starting Jan.1.

Richard Burnett, chief executive of the Road Haulage Association, said on Wednesday there was an 80% chance of “chaos in Kent,” the English county that contains the major Channel port of Dover, on Jan. 1, even with a trade deal.

He said work to build new customs facilities and border technology was behind schedule.

“The devil is in the detail, and some of the fundamental things that need to change and some of the things that need to be invested in are simply not happening fast enough,” he told Parliament’s Brexit committee.

Associated Press