Democratic Unionist Party (DUP) Brexit spokesman Sammy Wilson said on Friday that regulations were settled in Europe and imposed on Northern Ireland in a move that 'breaks the Union', Reuters reported.
The spokesman also noted that UK Prime Minister's Theresa May stance in negotiations is a betrayal and she has breached the promise.
"That to us is a breach of the promise which has been made that we would not be cut off from the rest of the United Kingdom," he said.
Wilson stated that the DUP hoped to turn PM May around, stressing that it was not too late to change her mind.
Earlier, Reuters reported, citing a letter from UK Prime Minister Theresa May obtained by The Times, that the EU was considering the creation of a customs border in the Irish sea between Northern Ireland and the rest of the United Kingdom in the event of a no-deal on Brexit.
The United Kingdom will leave the European Union on March 29, 2019, with the transition period set to end in December 2020. Nevertheless, London and Brussels still have not reached agreement on a number of issues, such as the Irish border and post-Brexit economic relations between the UK and the EU.