Northern Ireland’s First Minister Paul Givan is expected to announce his resignation, media reported on Thursday, after a renewed row over post-Brexit trade in the province.

BBC, Sky News and the domestic Press Association news agency quoted an unnamed Democratic Unionist Party (DUP) source as saying Givan could quit as early as Thursday afternoon.

There was no immediate official confirmation from the DUP, which is Northern Ireland’s largest pro-British unionist party.

But its leader, Jeffrey Donaldson, has threatened to collapse the power-sharing devolved government in Belfast in protest at the trading arrangements.

On Wednesday night, the DUP’s Edwin Poots, who holds the assembly’s agriculture portfolio, said he had ordered a halt on port checks of goods from mainland Great Britain.

The controls are part of the so-called Northern Ireland Protocol to prevent unchecked goods from entering the European single market by the back door via neighbouring Ireland.

The DUP claims the protocol, signed separately from the Brexit trade and cooperation agreement between the UK and EU, is harming businesses in Northern Ireland.

It also argues the Irish Sea checks drive a wedge between it and the three other UK nations, threatening Northern Ireland’s place as part of the whole country.

Poots’ move — branded a “stunt” by opponents — came as UK Foreign Secretary Liz Truss was due to hold talks with European Commission vice-president Maros Sefcovic.

Brussels described the move as “unhelpful”, saying it “creates further uncertainty and unpredictability for businesses and citizens in Northern Ireland”.

A European Commission spokesperson said the agreement was “the one and only solution” to safeguard the 1998 peace deal that ended 30 years of violence over British rule.

As part of that deal, an open land border was mandated between Northern Ireland and EU member Ireland to the south.

If Givan goes, after just eight months in the job, deputy first minister Michelle O’Neill, from the pro-Ireland nationalist Sinn Fein party, would also have to quit.

Other ministers in the devolved administration at Stormont could stay in place, but the executive would be unable to make any significant decisions, including on its budget.

Northern Ireland is gearing up for keenly watched assembly elections in May, with the DUP trailing Sinn Fein in opinion polls.