DUP MP Ian Paisley has said he will vote against the Government on the first Commons vote on the new post-Brexit deal on trading arrangements for Northern Ireland - known as the Windsor Framework.
MPs will vote on secondary legislation this week that would give effect to the "Stormont brake" mechanism within the framework.
The brake would allow a minority of MLAs at Stormont to formally flag concerns about the imposition of new EU laws in Northern Ireland - a move that could see the UK government veto their introduction in the region.
Read more: DUP leader Jeffrey Donaldson sets up panel to consult on Windsor Framework deal
The DUP is currently blocking devolution at Stormont in protest at the terms of the post-Brexit Northern Ireland Protocol. While the party says the Windsor Framework has gone some way to address its concerns, it says some "fundamental problems" remain with the new accord.
In an interview with the News Letter, Mr Paisley said: "I am categorically voting against, and I would be surprised if my colleagues do not join me."
He added: "My initial reaction to the Windsor Framework was that I didn't think it cut the mustard in terms of addressing our seven key tests (on restoring NI's place within the UK internal market).
"After taking time to study it and a least one legal opinion on it, and going through the details, and also having conversations and messages back and forward to the Secretary of State, I am still of that opinion - that it doesn't address any of our seven tests.
"It is the old substance dressed up in a new package with a ribbon around it, but it hasn't actually changed, or addressed the fundamental issue of Northern Ireland trade being disrupted in our internal UK market."
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