Stormont ministers clashed over Irish Sea port checks during robust exchanges on Tuesday.

The checks are taking place at existing repurposed buildings and other temporary facilities.

A DUP Stormont powersharing minister was challenged by devolved executive colleagues over his controversial decision to halt work on permanent post-Brexit inspection posts.

Sinn Fein Finance Minister Conor Murphy said: “The DUP must shoulder its responsibility for the active role they played with the Tories in creating these circumstances we are now living with, despite the majority of people and MLAs (Members of the Legislative Assembly) opposing their approach.

“It is time the DUP was honest with the public and accepted that the executive is legally obliged to comply with the commitments set out in the Withdrawal Agreement and the protocol, both of which now form part of the law.”

Stormont Agriculture Minister Gordon Lyons did not table a formal paper on his plans to the ministerial executive on Tuesday, and was asked by other ministers to confirm or provide details on what actions he has actually taken.

Northern Ireland is continuing to follow the EU’s trade rules to prevent a hard border on the island of Ireland as part of the Northern Ireland Protocol.

That has disrupted some trade from Great Britain, since Brussels requires extra checks on the Irish Sea to ensure compliance with Europe’s single market standards.

Permanent checking facilities are due to be built at Belfast, Larne, Warrenpoint and Foyle ports.

Physical construction has not begun at any of the sites, with work still in the design and preparatory phases.

The DUP and other unionist parties in Northern Ireland are pushing for the protocol to be ditched, claiming it has driven an economic wedge between the region and Great Britain which undermines the union.

The move by DUP Agriculture Minister Gordon Lyons to abandon the building projects at the ports was debated at Stormont on Tuesday.

The minister said: “A lot of people want to put their heads in the sand.

“We do face fundamental questions, we have fundamental concerns and challenges.”

Ministers from Sinn Fein, the SDLP and Alliance Party, the three pro-remain executive parties, contend that he does not have the authority to act unilaterally on issues considered significant or controversial.

Rival Stormont Assembly members have accused Mr Lyons of stunt politics.

He listed a series of problems with the protocol, including:

– Red tape and additional bureaucracy;

– Reduction in consumer choice;

– Problems facing hauliers transporting goods from Great Britain;

– Creation of barriers within the UK’s internal market;

– Businesses in Great Britain feeling they are not able to trade because of extra costs;

– Restrictions on livestock movements;

– Problems bringing guide dogs across the Irish Sea;

– Challenges transporting machinery.

Mr Lyons added: “It is so, so important that we get an alternative to the protocol.

“No amount of tinkering with it is going to make it work – it needs to go.”