Northern Ireland's Democratic Unionist Party announced Thursday it cannot support Boris Johnson's current Brexit plan, dealing a major blow to the British prime minister just hours before a crunch EU summit.
"As things stand, we could not support what is being suggested on customs and consent issues, and there is a lack of clarity on VAT (value added tax)," the DUP, which backs Johnson's government, said in a brief statement on Twitter.
"We will continue to work with the government to try and get a sensible deal that works for Northern Ireland and protects the economic and constitutional integrity of the United Kingdom."
Housing Secretary Robert Jenrick told BBC television: "We always knew these negotiations were going to be difficult and we're going to go down to the line."
"We want to provide sufficient comfort for the DUP and unionists in Northern Ireland to feel that the arrangements we would put in place with this deal are sufficient to give them comfort to support it."
"They would have to explain what on Earth the last two years have been about if they were to fold."