In a statement released after an emergency meeting in London, European Commission vice president Maros Sefcovic said Britain had ‘seriously damaged trust’ with Brussels.

He said ‘in no uncertain terms’ that the ‘timely and full implementation’ of the divorce deal is ‘a legal obligation.’

‘Violating the terms of the Withdrawal Agreement would break international law, undermine trust and put at risk the ongoing future relationship negotiations,’ the statement added.

But Michael Gove, who attended the meeting on behalf of the UK Government has hit back, saying the Government’s controversial Internal Market Bill ‘would not and could not’ be withdrawn.

In this piece of legislation, published on Wednesday, the Government proposed changes to Boris Johnson’s Brexit deal, which has already been ratified by parliament and agreed with the EU.

The bill would give UK ministers powers to overrule or ignore rules relating to the movement of goods from Northern Ireland to Great Britain, if this cannot be decided by a joint committee.

This is intended as insurance against a no-deal Brexit but undermines what has already been agreed.

The UK Government say the legislation is needed to protect the peace process in Northern Ireland but the EU says it will do the opposite.

Mr Sefcovic’s statement finished with a warning that the Withdrawal Agreement ‘contains a number of mechanisms and legal remedies to address violations of the legal obligations contained in the text – which the European Union will not be shy in using.’

The UK Government has responded by releasing its legal position relating to the proposed bill. It stated ‘honouring treaty obligations’ is a ‘key principle’ in the UK’s approach to international relations but these are ‘difficult and highly exceptional circumstances.’

The statement asserted that parliament is sovereign and can pass legislation which is in breach of the UK’s treaty obligations and would ‘not be acting unconstitutionally’ by doing so.

The Internal Market Bill will be formally debated by MPs in Parliament for the first time on Monday.

Lord Howard became the third former Conservative party leader to criticise the plans, while speaking in the House of Lords today.

He accused the Government of damaging the UK’s ‘reputation for probity and respect for the rule of the law’.

‘How can we reproach Russia or China or Iran when their conduct falls below internationally accepted standards, when we are showing such scant regard for our treaty obligations?’ he told his fellow peers.

The clash overshadowed the eighth round of trade negotiations between the EU’s chief negotiator, Michel Barnier, and his British counterpart, David Frost.

There are just five weeks to go until the October 15 deadline set by the prime minister for an agreement on a trade deal.