BRUSSELS — After years of negotiations, threats and missed deadlines, the European Union and Britain finally reached a Brexit trade agreement.

There was hope that the now-separated Britain would be able to navigate their relationship towards calmer waters with the 27-nation bloc.

One thing is certain as Christmas draws near again: it wasn’t meant to be.

On Tuesday, Britain’s Brexit minister accused the EU in wishing its former member failure and demeaning the U.K. as a country to be trusted. David Frost stated that the EU does not always want us to succeed and “get back together to constructive work.”

He stated that a fundamental rewrite to the mutually agreed divorce agreement was the only way for the “fractious” relationship to be fixed. And he warned Britain that it could push an emergency button on the deal to override any failures.

“We are constantly facing generalized accusations that our credibility is questionable and that we don’t have the ability to act as a reasonable international actor,” Frost said. Frost was responding to EU claims that Britain wants to undo the legally binding treaty it negotiated and signed.

Post-Brexit tensions have escalated into an intensifying fight over Northern Ireland. This is the U.K.’s only land border with an EU member, Ireland. The most contentious and delicate part of the Brexit deal is that Northern Ireland will remain within the EU’s single marketplace for trade in goods. This allows it to avoid a hard border between Ireland and EU member Ireland.

This means that customs and border controls must be carried out on goods coming to Northern Ireland from the U.K. despite the fact that they are one country. These regulations were designed to stop goods from Britain being allowed into the EU’s single market without tariffs. However, they will allow for an open border on Ireland which is a crucial pillar of Northern Ireland’s peace process.

The U.K. government quickly complained that the arrangements were not working and said the rules impose unnecessary red tape on businesses. A belligerent metaphor is not lacking in 2021. Britain asked the EU to lift a ban on imported British meat products like sausages into Northern Ireland.

The British Unionist community in Northern Ireland claims that the Brexit deal weakens the 1998 Good Friday Peace Agreement. This agreement sought to protect both Unionists and Irish Nationalist communities.

The bloc has accepted to examine changes to the Protocol and will present its proposals on Wednesday. Britain had previously raised the stakes, and Frost demanded that the Protocol be rewritten.

Frost stated that the Protocol was “not working” in his speech to the Portuguese capital.

He said, “It has lost all consent in Northern Ireland.” It isn’t doing what it was created to do, which is protect the Belfast (Good Friday Agreement). It is actually doing the exact opposite. It must change.

He also stated that the EU should remove the European Court of Justice from its role as final arbiter of trade disputes in Northern Ireland, and instead accept international arbitration. “The EU court’s role means that the EU can make laws in Northern Ireland without democratic scrutiny or discussion.”

It is unlikely that the EU will agree to the changes. The highest court of the bloc is considered the pinnacle for the free-trade single market. Brussels has pledged not to undermine that order.

Leo Varadkar (Ireland’s Deputy Prime Minster) said that Britain’s demands were “very difficult to accept.”

He stated that he didn’t believe we could ever find a situation in which another court would decide what the rules of a single market are.

Some EU observers believe Britain’s request to have the court’s oversight removed shows that it doesn’t care about making the Brexit deal happen.

Frost reiterated the threat by the U.K. to invoke Article 16, which allows either side to suspend an agreement in extraordinary circumstances. This would cause already strained relations to go into a deep freeze and could lead the U.K. to invoke Article 16, a clause that allows either side to suspend the agreement in exceptional circumstances.

The symbolically powerful but economically small subject of fish is also fueling divisions. It was the one that held up a trade agreement to the last minute last year.

France would like its EU partners to act together if London didn’t give more licenses to small French fishing boats that roam near the U.K. crown dependentencies of Jersey or Guernsey just off France’s Normandy coastline.

Last week, Jean Castex, the Prime Minister of France, accused Britain of breaking its promise regarding fishing.

He stated, “We see in the most clearest way that Great Britain doesn’t respect its own signature.”

Castex was speaking out in a relationship where both parties often resort to cliches about each other. He was recalling the centuries-old French insult “Perfidious Albion,” which refers to a nation that cannot be trusted.

The U.K. Brexit supporters are often seen across the English Channel as a conniving EU, hurting by Britain’s departure and doing everything it can to make Brexit less successful by putting up bureaucratic obstacles.

Frost acknowledged that “the EU and I have entered a low equilibrium. (A) somewhat fractious relation.” Frost acknowledged that it doesn’t have to be this way all the time, but it does take two to fix it.