BELFAST, Northern Ireland (AP) _ Talks between Protestants and Catholics on trying to keep the peace in Belfast on Northern Ireland's most divisive holiday broke down Tuesday.

The failure to come to an agreement about how to avoid violence on the Twelfth of July in Belfast set up a possible confrontation Wednesday between Protestant marchers and Catholic protesters.

At issue is the right of the Protestant Orangemen to lead a march celebrating British rule over the province through areas populated by Catholics _ many of whom oppose British rule.

Despite the breakdown, the talks had been seen as a sign that times are slowly changing and that compromise should be favored over confrontation. Never before have the Orangemen negotiated with Catholics about their British flag-waving summer marches.

A minor success came Tuesday in Portadown, a pro-British Protestant town, when both sides permitted a quiet Orange Order march through a Catholic neighborhood.

But in Belfast, anti-march protesters said they would block off a bridge that connects their Catholic neighborhood with Protestant parts of Ormeau Road. About 350 Orangemen expect to walk its full length, as they have done for nearly two centuries, to downtown Belfast for a far bigger march.

``As soon as we see or hear the Orangemen coming we will block the road,'' said Richard Pelan, 28, a protest organizer who expected reinforcements from other Catholic parts of the city but no violence from their side.

``The Orange Order have the attitude that they'll march down that road whatever it takes, but we will be peaceful protesters. If the Orangemen want a fight they can have it with the RUC,'' he said of the Royal Ulster Constabulary, Northern Ireland's mostly Protestant police force.

Orangemen predicted the Catholics' challenge would attract thousands of Protestants to their aid and force police to push the Catholics out of the way.

``It was never our intention to shove a march through. We were prepared to work with them, but we're into a confrontation now,'' said Noel Liggett, secretary of Orange Order District No. 10 in south Belfast, who had negotiated with Catholic protesters since April.

The huge Orange demonstrations, which since the early 19th century have demonstrated Protestant determination to uphold their faith under the British Crown, always increase tensions with the province's Catholic minority.

About 20 marches by the more than 80,000 members of Northern Ireland's largest fraternal order will bring much of the British-ruled province to a standstill Wednesday.

This year, on the heels of the Irish Republican Army's 10-month-old truce and rising demands for equal treatment under the law, Catholics are aggressively trying to block Orange marches into their areas.

Ormeau Road protesters stopped six smaller Protestant marches this year while they pursued negotiations with the Orangemen.

But last week, marchers clashed with police on the same Ormeau bridge that is likely to feature in Wednesday's showdown. Rank-and-file Orangemen vowed they wouldn't be pushed around on the Twelfth.

In Portadown, Catholics ended a stubborn sit-down protest Tuesday after being assured that the Orangemen would consult them on future marches. Some Orangemen later crowed that they'd conceded nothing.

The protesters on Sunday forced police to stop the march for the first time in 188 years. Protestants from all over Northern Ireland converged on the site demanding that police let them through.

On Monday, several hundred Protestants tried to outflank riot police. Several people were wounded as rocks, bottles and paint bombs filled the air; police responded with plastic bullets.

Tension rose overnight as Orangemen massed outside the Catholic area and drummed relentlessly on shoulder-height Lambeg drums.

The Catholic crowds, who blocked the road for nine hours Tuesday, parted as the Protestants' scaled-down procession arrived and watched in stony silence from the sidewalk. Some protesters felt that for the first time they had earned the right to be consulted. Others felt disappointed.

The Catholics cheered as the final Orangemen passed. The Protestants cheered, too, once they reached the end of the Catholic neighborhood and were welcomed by an even bigger crowd of Orangemen underneath an arch that read: ``Fear God, Honor the King.''