DOWNING Street has insisted a post-Brexit free trade deal with the EU is still possible despite an increasingly bitter war of words with Brussels amid threats of legal action.

The European Commission has given the UK until the end of the month to drop legislation enabling ministers to override provisions in the Brexit Withdrawal Agreement relating to Northern Ireland.

Following a stormy meeting in London on Thursday, the commission warned the UK was putting trade talks at risk and said it would “not be shy” of taking legal action.

The Prime Minister’s official spokesperson reiterated the Government’s position that the provisions in the Internal Market Bill remained “critical” to the preservation of the Northern Ireland peace process.

He said the UK would continue to strive for an agreement and called on the EU to show greater “realism”.

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“We have engaged constructively with the EU throughout this process. We have negotiated in good faith and we will continue to do so,” the spokesperson said.

“We do still believe that there is a deal to be reached. We will work hard to achieve it.

“What we have been asking for is for more realism on the EU side about what it means for the UK to have left the EU and to once again be a sovereign nation.”

Amid the worsening atmosphere between London and Brussels, it emerged the EU had even raised the prospect that it could block exports of animal products from the UK once the current Brexit transition period comes to a close at the end of the year.

In a statement following the latest round of talks on Thursday, EU chief negotiator Michel Barnier said there were “many uncertainties” about the UK’s animal hygiene regime.

He said “more clarity” was needed if Britain was to receive the “third-country listing” entitling it to export animal products to the EU.

On the British side, there was surprise at the comments as the UK continues to apply EU standards, although it is understood the issue has been raised previously in the negotiations.

A Government spokesperson said: “The right to export is the absolute basis for a relationship between two countries that trade agricultural goods.

“It is a licence to export and entirely separate from the issue of food standards. It would be very unusual for the EU to go down this route and deny the UK listing.”

In Brussels, the European Commission’s chief spokesperson Eric Mamer said they would consider what action to take if at the end of the month the UK had still not withdrawn the provisions in the Internal Market Bill.

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“We have set a deadline for the UK. We are going to take this step by step. We are going to wait for the reaction of the United Kingdom by that deadline,” he said.

“We will consider next steps once we have reached that particular bridge.”

Meanwhile, Gordon Brown joined fellow former prime ministers Theresa May and John Major in condemning the Government’s plan, describing it as “a huge act of self-harm”.

“You can’t expect to have a decent negotiation with the European Union if you start by breaking a treaty that you signed yourself and negotiated only a few weeks ago,” he told ITV’s Good Morning Britain.

However, some Tory Brexiteers were urging Johnson to go even further and to abandon the Withdrawal Agreement altogether.

Former minister Steve Baker said: “I think we should now be willing to repudiate the whole treaty on the basis of the EU’s bad faith, which in my mind is undoubted.”