DUP MP Sammy Wilson has stepped down as his party’s chief whip in Westminster.
The unionist politician has been an outspoken critic of the agreement reached between his party and the UK government over post-Brexit trading arrangements last month, which led to the return of power-sharing in Stormont.
However, it is not yet clear if his stance on the deal led to his exit from the frontbench.
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The DUP has always taken a pro-Brexit stance, but was left angry at the trade agreement reached between the UK and EU that effectively created a border in the Irish Sea.
As a result, the party refused to return to the Northern Ireland Assembly until changes were made to make it easier for businesses to trade with the rest of the UK.
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After almost two years of stalemate, DUP leader Sir Jeffrey Donaldson signed off a new plan at the end of January, which included replacing the so-called “green lane” for goods being sent across the Irish Sea with a UK internal market system.
He said the system “reflects the reality that Northern Ireland is part of the United Kingdom”.
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The agreement paved the way for Northern Ireland’s executive to return in early February, with Michelle O’Neill appointed as Sinn Fein’s first ever first minister.
But Mr Wilson, who has represented East Antrim since 2005, criticised the deal, saying UK ministers were part of a “spineless, weak-kneed, Brexit-betraying government, refusing to take on the EU and its interference in Northern Ireland”.
Sky News has contacted Mr Wilson and the DUP for comment.