A British Government department is to intervene in a High Court challenge to DUP minister Edwin Poots’ decision to order a halt on Irish Sea border checks, it has emerged.

The Department for Environment, Food and Rural Affairs (DEFRA)’s involvement was confirmed as the case was listed for full hearing in September.

Legal action is being taken against Mr Poots for instructing his officials in February to stop inspections on goods entering Northern Ireland from Great Britain.

Mr Poots, the farming minister, said he had received legal advice that he could direct a halt in the absence of approval for the checks from the wider Stormont Executive.

His decision is being challenged by a Sinn Fein member who has been allowed to keep their identity secret (in spite of a challenge to their anonymity by the News Letter), as well as another applicant named Edward Rooney, and Belfast City Council.

They claim the Stormont administration allocated implementation of the checks to the Department of Agriculture, Environment and Rural Affairs (DAERA).

The step taken by the minister was allegedly so significant and controversial that it required consent from the full Executive.

Proceedings were put on hold last month amid new claims that Mr Poots’ department may never have been under a legal obligation to carry out the checks.

At a further hearing on Friday it was confirmed that Whitehall wants to intervene in the case, with senior counsel instructed by DEFRA to make submissions about checks on goods and animals coming into Northern Ireland.

With counsel for Mr Poots, John Larkin QC, pressing for the case to be dealt with as soon as possible, Mr Justice Colton agreed to list the challenge for a two-day hearing in September.

Meanwhile, the checks are to continue under judicial order until a final determination is made.

Solicitor Ciaran O’Hare of McIvor Farrell, representing the Sinn Fein member, said “my client is pleased that his case has now been listed for a full judicial review hearing”.