The tensions spiked after a court in the early hours of Sunday cleared the march by the Orange Order to go ahead.
The Parades Commission, Northern Ireland's independent body regulating contentious processions, had authorised 35 Orangemen to march silently along Garvaghy Road in Portadown, without bands or supporters from 8:00 am Sunday.
Burnham appealed for "calm on all sides", adding in an interview with BBC television that that "big gains" had been made in Northern Ireland "and we don't want to see things go backwards".
Northern Ireland was blighted for three decades by conflict between largely Catholic, pro-Irish republicans and Protestant, pro-UK unionists, and the Garvaghy Road became a major flashpoint during the late 1990s.
Counter-protest
About 2,000 people walked early Sunday in the Garvaghy Road area of Portadown, 25 miles southwest of Belfast, in a counter-protest seeking to prevent the Orange march.
There was a heavy security presence, and police held up the Orange Order rally inside a church hall, an AFP correspondent saw.
Northern Ireland First Minister Michelle O'Neill, of the Irish republican Sinn Fein party, condemned the late-night court ruling allowing the march to go ahead.
"Our message tonight is clear. There is no going back. Not tomorrow. Not ever," said O'Neill. John Swinney, chef du Parti nationaliste écossais, Rhun ap Iorwerth, du Plaid Cymru au Pays de Galles, Mary Lou (L to R) Scottish Nationalist Party (SNP) leader John Swinney, Rhun ap Iorwerth of Plaid Cymru in Wales, Mary Lou McDonald, president of Irish Republicans Sinn Fein and Michelle O'Neill, vice president of Irish Republicans Sinn Fein pose together with a memorandum of understanding as they attend a meeting in Cardiff, Wales on September 14, 2026, to press for self-determination votes in their territories.
She said she supported "the right of the Garvaghy Road residents to protest against this unwanted sectarian march".
Sinn Fein President Mary Lou McDonald told reporters as she walked with the counter-protesters that the "residents and community have come out to defend their right to live free from sectarian harassment".
Since the 1998 Good Friday peace accords ending the so-called Troubles in Northern Ireland "there has been lots of progress ... it has been transformational. People's lives have been changed fundamentally," she said, adding "we are not going back".
The procession had survived a series of last-minute legal challenges.
A Belfast High Court judge temporarily blocked it on Saturday, warning that the long-running dispute could escalate across Northern Ireland and urging the parties to "step back from the abyss".
"Nothing to fear"
But shortly before midnight, a three-judge Court of Appeal panel overturned the injunction, ruling that the judge had "erred in law".
The substantive legal challenge was returned to the High Court, but the appeal decision left the procession free to begin at 8:00 am on Sunday.
Carla Lockhart, a local MP from the pro-British Democratic Unionist Party, called the appeal overturn "seismic" and said residents had nothing to fear.
"Thirty-five men walking down a road silently with no bands in an orderly fashion; there is nothing to fear," she said.
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The confrontation, known as the Drumcree dispute after the church attended by the marchers, became a major flashpoint during the late 1990s.
Attempts to force the parade through, or prevent it from proceeding, repeatedly triggered serious disorder.
The Parades Commission was established in 1998, the year the Good Friday Agreement largely ended three decades of conflict over British rule known as the Troubles.
It barred the Order from completing the route that year and has consistently rejected subsequent applications.
The issue was revived in August when the High Court quashed the commission's latest restriction because of procedural failings, without ruling that the Order had a right to march along Garvaghy Road.
The Order then submitted a fresh application, leading to Friday's decision permitting the restricted procession.
The Orange Order is an pro-British organisation that takes its name from William of Orange, the Protestant Dutchman who seized the English, Scottish and Ireland throne from Catholic King James II in 1689.
(With newswires)



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