Leader Mike Nesbitt said his Ulster Unionist Party (UUP) had decided on Saturday to withdraw its sole minister from the Northern Ireland Executive, which has 13 ministers and combines five different parties.

"This decision was unanimous," Nesbitt said, adding that UUP regional development minister Danny Kennedy would formally resign from cabinet next week.

On 12 August, former IRA member Kevin McGuigan was killed in Belfast. Police assessed that the IRA might have been involved.

In recent days, the UUP and the larger Democratic Unionist Party (DUP) have demanded the departure from cabinet of Sinn Fein, which denies the existence of the IRA, its one-time armed wing.

Disarming the republican paramilitary group was a central part of the so-called Good Friday accord reached in 1998.

That deal largely ended three decades of sectarian conflict between mostly Catholic nationalists, who favored unification with the Republic of Ireland, and Protestant unionists wanting Northern Ireland to remain within the United Kingdom.

Disagreements have frequently emerged between the unionist and nationalist blocs that control the Northern Irish parliament.

Sinn Fein denies lingering IRA

On Thursday, DUP deputy leader Nigel Dodds said that when the Northern Ireland Assembly returned from its summer recess to Belfast's Stormont (pictured above), the DUP would call a vote to exclude Sinn Fein from government.

So far, the Social Democratic and Labour Party (SDLP), the second largest nationalist group in Northern Ireland's power-sharing structure, say any expulsion of Sinn Fein would be premature.

Sinn Fein leader Gerry Adams has insisted that the IRA has "gone away."

Sinn Fein leaders have also said that if any former IRA members were involved in the murder of McGuigan then they must be prosecuted.

If the larger DUP were to leave the executive, the governance of Northern Ireland could revert to London and cause a political rift.

ipj/jr (Reuters, dpa, AFP)