Members of Northern Ireland's two largest pro-British parties are set to take part in legal action challenging part of Britain's divorce deal with the European Union, the parties said on Sunday.
The Democratic Unionist Party (DUP) and Ulster Unionist Party (UUP) are to join other pro-British figures to challenge the Northern Ireland Protocol, which has created trade barriers between the British region and the rest of the United Kingdom.
The protocol, which is designed to protect the European Union's single market without creating a land border on the island of Ireland, has caused significant disruption to trade since it came into force at the start of the year.
Some British companies have halted deliveries to Northern Ireland and some supermarkets have been left with empty shelves.
The DUP said several senior members would join "other likeminded unionists" as named parties in judicial review proceedings challenging the Northern Ireland Protocol’s compatibility with Act of Union 1800, the Northern Ireland Act of 1998 and the Belfast Agreement, it said in a statement.
"Neither the Northern Ireland Assembly, the Northern Ireland Executive nor the people of Northern Ireland consented to the Protocol being put in place or the flow of goods from GB to NI being impeded by checks," said DUP leader and Northern Ireland First Minister Arlene Foster.
The protocol was part of an international agreement signed by Prime Minister Boris Johnson last year.
The region's second largest pro-British party, the Ulster Unionist Party, said in a statement it would 'seek to explore every political and legal avenue to get the NI protocol annulled.'