A unionist has called for co-operation with the Republic of Ireland to be frozen and work implementing the post-Brexit Northern Ireland Protocol to be abandoned.
The DUP should stop officials operating Irish Sea port checks on goods from the rest of the UK, Traditional Unionist Voice (TUV) leader Jim Allister added.
Mr Allister is his party’s representative at the Stormont Assembly and has a number of local councillors.
He has been a persistent critic of the large unionist parties and devolved powersharing with Sinn Fein over many years.
Mr Allister said: “Underpinning Stormont, we are told, is the equilibrium of the north/south and east/west arrangements.
“With the east/west relationship being trashed by the operation of the Protocol, the DUP and UUP, as key operatives of the north/south arrangements, should freeze their involvement until the east/west equilibrium is restored.”
The North South Ministerial Council allows all-Ireland co-operation on issues like tourism and management of waterways.
Its members meet regularly.
Northern Ireland is continuing to follow some of the EU’s rules despite Brexit, to prevent the establishment of a hard border on the island of Ireland.
DUP agriculture minister Edwin Poots’ officials are conducting checks on some animal products arriving at ports in Belfast and Larne.
Hauliers have faced difficulties transporting stock to Northern Ireland from the rest of the UK amid extra paperwork requirements.
Mr Allister said: “It is surely as incongruous as it is complacent to continue to work north/southery while our east/west links are emasculated.
“Accordingly, I suggest unionist parties within the executive should publicly and jointly refuse to operate the north/south arrangements unless and until the protocol is addressed.”
The institutions for co-operating with the Republic of Ireland and with the rest of the UK were created by the 1998 peace agreement.
Mr Allister asked: “How often have we heard about the sanctity of the Belfast Agreement ‘in all its parts’?
“Well, does the east/west part not matter? It’s time to put it to the test.”
Mr Allister said the adverse constitutional impact of the protocol was obvious.
“The infrastructure of the Irish Sea border is the physical manifestation of not just the partitioning of the UK but the locking of Northern Ireland into the economic orbit of the Republic/EU.”