Belfast, Northern Ireland ? Northern Ireland’s main Protestant party on Saturday rejected a British deadline to share power with Catholics, officials said, launching a showdown that could end in the collapse of the territory’s legislature.

More than 100 officials from Ian Paisley’s Democratic Unionist Party voted overwhelmingly to reject Britain’s long-held demand for a 12-member administration to be formed and receive powers by Monday, according to officials in both the party and the British government, speaking anonymously because negotiations between the two sides were continuing.

Britain insists the Northern Ireland Assembly will be shut down immediately in favor of intensified Irish government involvement in the British territory if the Monday deadline is missed.

The officials said Paisley and British Prime Minister Tony Blair were involved in last-minute telephone negotiations. They said the Protestant party called on Britain to pass an emergency bill to delay the deadline until May. In exchange, Paisley would agree to meet for the first time with Gerry Adams, leader of the major Catholic-backed party, Sinn Fein.

Adams said Britain must stick to the deadline and give no more time to Paisley.

“There will be deep disappointment and dismay at the failure of leadership by the DUP and their efforts to frustrate the will of the people,” Adams said.

The 108-member assembly, which was re-elected only two weeks ago, was designed to form a 12-member, four-party administration that would take control of Northern Ireland government departments from Britain. Such cross-community cooperation was supposed to be the centerpiece of the province’s 1998 peace accord but has failed since 2002 amid Protestant hostility to Sinn Fein.

Paisley declined to discuss specifics of the party’s motion – but emphasized he would not be coerced by Britain’s deadline, saying Protestants “will be persuaded but they are not going to be driven.”

In Dublin, Adams canceled a planned news conference and traveled north to meet Northern Ireland Secretary Peter Hain and other British officials. Hain faced his own midnight deadline – to issue an order that would permit power to be transferred Monday from himself to local hands.

The Democratic Unionists say they will work with Sinn Fein only if the party’s leaders demonstrate convincing support for law and order.

Sinn Fein, which supported the Irish Republican Army’s 1970-1997 campaign to overthrow Northern Ireland by force, in January voted to open normal relations with Northern Ireland’s mostly Protestant police.

But the political messages and events in Sinn Fein power bases since have been mixed.

Adams has repeatedly called on supporters to help police solve specific crimes and certain categories of crime, such as drug dealing and rape, but also has defended a deputy’s view that police should not be told about the activities of IRA dissidents plotting to wreck the 1997 cease-fire.

And police units have continued to face violence in hard-line Catholic parts of Northern Ireland, including overnight.

Police said men and youths threw more than a dozen gasoline bombs early Saturday at a police station in Crossmaglen, a border town renowned as an IRA bastion, causing scorch damage to perimeter walls but no injuries.