Northern Ireland's First Minister, Paul Givan, resigned on Thursday in protest against post-Brexit trade rules.

His resignation comes after Northern Ireland's Agriculture Minister Edwin Poots on Wednesday tried to block the inspection of goods arriving from other parts of the UK.

It would have violated the Brexit agreement between Britain and the European Union, but the checks continued on Thursday.

"Our institutions are being tested once again,'' Givan said.

"They have been impacted by the agreement made by the United Kingdom government and the European Union, which created the Northern Ireland Protocol," he added.

The Democratic Unionist Party's (DUP), which Givan belongs to, opposes the Northern Ireland Protocol, which mandates the checks and is designed to prevent a hard border between the Republic of Ireland and Northern Ireland.

The pro-British DUP has previously threatened to collapse the devolved government in protest against the protocol.

Northern Ireland elections loom

Givan's resignation means Northern Ireland's Deputy First Minister Michelle O'Neill, of pro-Irish nationalist party Sinn Fein, automatically loses her position under Northern Ireland's power-sharing arrangements.

Other ministers at Northern Ireland Assembly can stay in place, but they cannot make any significant decisions, including on the budget.

Sinn Fein leader Mary Lou McDonald immediately called for new elections.

"We cannot stagger on in the months ahead without a functioning executive, and Sinn Fein will not facilitate this," McDonald said.

Elections are scheduled to be held in May.

The UK secretary of state for Northern Ireland, Brandon Lewis, described Givan's resignation as "extremely disappointing" and called for him to rethink.

Irish Foreign Minister Simon Coveney said Givan's decision was "deeply regrettable," urging all leaders in Northern Ireland to avoid "any new cliff edges or instability."

lo/rs (AP, AFP, Reuters)