THE UK has refused refuse to implement the Northern Ireland Protocol in full despite a legal deadline expiring today, heightening the prospect of a trade war with Brussels

Instead, the UK will unilaterally continue with ‘grace periods’ on checks on goods covered by the post-Brexit trading arrangement. 

It means the European Commission could now take the dispute to the European Court of Justice, which could fine the UK. 

The Commission could also impose trade sanctions, resulting in a tit-for-tat with London.

The EU launched three infringement proceedings in June and a further four in July, claiming the UK was in “non-compliance” with “significant parts of the Protocol”.

London was given until the end of today to ensure compliance with anti-smuggling checks, excise duties, VAT with e-commerce and other measures deemed “essential” to Northern Ireland keeping its “privileged access to the EU single market”.

Despite politics being largely on hold after the Queen’s death, Britain’s mission to the EU formally replied, with the PA news agency reporting the response said the UK would stick with the current approach of not forcing retailers and exporters to adhere to all the agreed checks.

The response is liable to anger the bloc, which has stressed the need to find joint solutions, but Britain argues a delay can help create the space for those solutions to be found.

The EU is already angry about the UK's threat to override parts of the protocol with new legislation, which Brussels argues would break international law.

Commission president Ursula von der Leyen will be in Westminster for the Queen’s funeral on Monday, when Liz Truss is due to meet some leaders for political talks.

However it is not yet clear if Ms von der Leyen will be one of the PM’s appointments.

There have been unconfirmed suggestions that Ms Truss will speak to Irish Taoiseach Micheal Martin on the margins of the funeral amid tensions over the protocol.

The European Commission declined to discuss the contents of the UK letter, as did the UK Government during the mourning period. Neither side was planning to publish the document.

Commission spokesman Daniel Ferrie saids: “I can confirm we have received a reply from the UK. We will now analyse the reply before deciding on the next steps.”

The Protocol - which Boris Johnson signed off as Prime Minister in order to "get Brexit done" - requires regulatory checks and customs declarations on goods moving between Great Britain and Northern Ireland, as they could flow on through the open border with Ireland into the EU single market.

This effectively means there is a trade border in the North Sea between NI and GB.

Seen by Unionists as a threat to the integrity of the UK, the protocol’s continued operation has resulted in the DUP blocking a return of the power-sharing executive at Stormont.