The leader of Northern Ireland's largest party said Thursday that he believes the majority of his Protestant supporters are ready to vote for an agreement for sharing power with Catholics.

"It is the best deal that is available, warts and all. There isn't a better one available and there isn't a realistic alternative," said David Trimble, leader of the pro-British Ulster Unionist Party.Trimble failed to get an endorsement for the agreement Wednesday from the Grand Lodge of the Orange Order, the largest Protestant fraternal organization in Northern Ireland. At the same time, Protestant firebrand Ian Paisley launched his campaign for a "no" vote on the agreement in the May 22 referendum in both parts of Ireland.

Trimble said one of the key gains is that all parties to the agreement - including the IRA-allied Sinn Fein party - would be obliged to recognize the legitimacy of British rule in Northern Ireland, and to affirm that any change in that status would require consent from a majority of the province's people.

An opinion poll published Thursday in The Irish Times and The Guardian newspaper in London supported Trimble's optimism, showing that 73 percent of those surveyed intended to vote for the agreement, compared to 14 percent who intended to vote no.

The Harris Research Center interviewed 500 people Saturday and Tuesday by telephone, and the sampling error was about 3 percentage points.

Though that's just one poll, with still more than a month to go before the referendum in Northern Ireland, it will hearten Trimble's supporters as they prepare for a vote by the Ulster Unionist's 800-member governing council Sat-ur-day.

Last weekend, Trimble got a 72 percent "yes" vote from the party executive. At a news conference this morning, he brushed aside a question about whether he would resign if he lost the vote, and said he expected an even larger majority Saturday.

Trimble added that he believed more than 70 percent of the voters would support the agreement in the referendum. Anything less than 60 percent would bode ill for the success of the new power-sharing structures to be set up to govern Northern Ireland, he said.

The Grand Lodge of the Orange Order, historically aligned with Trimble's party, said Wednesday it could not urge its 50,000 members to support the deal until it knew more about provisions for early release of paramilitary prisoners and reforming the Royal Ulster Constabulary, Northern Ireland's predominantly Protestant police force.