A High Court judge in slotxo หน้าเว็บ Belfast has ruled that the Northern Ireland Protocol is lawful.
A group of unionist politicians had challenged the protocol in judicial review proceedings, claiming it conflicted with the 1998 Good Friday Agreement and the Acts of Union.
Mr Justice Colton rejected their challenge on all grounds on Wednesday afternoon.
Politicians have been giving their reactions to the ruling.
Prime Minister Boris Johnson
Mr Johnson said the government would "study in detail" the High Court ruling, after being asked about it during Prime Minister's Questions by DUP MP Iain Paisley.
Speaking in the House of Commons, Mr Johnson said: "I can give him this general assurance, which he knows to be true, is that nothing will effect the position of Northern Ireland as part of the United Kingdom.
"We will make sure we uphold that."
Sir Jeffrey Donaldson, Democratic Unionist Party leader designate
Sir Jeffrey described the ruling as "politically significant" and said it would have potential consequences for "the future stability of political institutions".
In a tweet, the Lagan Valley MP said the judgement confirmed the "protocol damages our constitutional position in the UK contrary to the principle of consent and various agreements".