BELFAST, Northern Ireland -- Their options narrowing and patience wearing thin, the British and Irish governments are demanding an Irish Republican Army commitment to disarm within days -- or else Northern Ireland's Protestant-Catholic administration will be suspended.

The prime ministers of Britain and Ireland, Tony Blair and Bertie Ahern, spent two hours in an emergency meeting late Thursday discussing how best to defend the 1998 Good Friday peace accord and its key institution, the power-sharing Cabinet formed just nine weeks ago.Afterward, side-by-side, they voiced the same message.

The question of when, if ever, the IRA will disarm "has to be confronted once and for all," Ahern said.

A report Monday by an independent disarmament commission confirmed that its past two months of secret contacts with IRA negotiators had achieved no concrete progress.

The verdict has shaken the foundations of the Cabinet, a four-party coalition that requires the province's major British Protestant party, the Ulster Unionists, to work with the IRA-linked Sinn Fein.

Ulster Unionist leader David Trimble says his party will withdraw, collapsing the Cabinet, unless the Cabinet's powers are rescinded pending an IRA arms move.

The British government has responded, calculating that a Cabinet rendered powerless might still be kept intact, whereas a collapsed one might never be reassembled.

Announcing his plans to present legislation today to return "direct rule" to London, Britain's Northern Ireland Secretary Peter Mandelson urged the Ulster Unionists to wait and see whether the IRA would shift its position.

He said it would take about a week for the bill to pass through Parliament, then it would be enacted "unless events between now and then clearly make this unnecessary."

In November, after a year of deadlock, American George Mitchell persuaded the Ulster Unionists to form the Cabinet in exchange for assurances that the IRA would gradually give up its weapons stockpiles in response. The Good Friday accord anticipated the IRA's total disarmament by May.

Mandelson said it was "clear that if there was no (weapons) decommissioning in January then the Ulster Unionists would be unable to sustain their involvement in the Executive (Cabinet). There was no ambiguity about that."

He called the IRA's position "simply unacceptable, and a betrayal of the entire community in Northern Ireland."

The turn of events put Sinn Fein leaders firmly on the defensive.

They responded angrily, accusing other major players in the peace process -- the British government, the Ulster Unionists and the major Catholic-supported party, the pacifist Social Democratic and Labor Party or SDLP -- of all violating the letter of the Good Friday accord.

Sinn Fein leader Gerry Adams accused Mandelson of being "prepared to cave into the demands of the unionists" and of dealing "a slap in the face to the Sinn Fein leadership."

But the SDLP's Mark Durkan, finance minister in the Cabinet, said Sinn Fein and the IRA appeared determined that everybody else should fulfill their obligations within the accord -- but didn't apply the same standard to themselves.

"We all want the administration to survive. Equally we want the disarmament commission to be successful in achieving decommissioning," Durkan said. "We're not going to get one without the other. And everyone should be deeply concerned that the commission has reported a failure on the IRA's part.