A Belfast High Court appeal by the Garvaghy Road Residents’ Coalition to stop the Orange Order march in Drumcree has been put back to Monday to facilitate ongoing talks.

The hearing had been due to take place on Friday. The postponement comes as residents travelled to Hillsborough Castle on Thursday night for talks with Northern Secretary Chris Bryant in an attempt to break the deadlock.

The Drumcree policing operation has cost about £3 million (€3.5 million) so far, Police Service of Northern Ireland (PSNI) chief constable Jon Boutcher said earlier on Thursday.

Addressing the Northern Ireland Policing Board in Belfast, Boutcher also warned that the consequences of forcing an Orange Order march down the Garvaghy Road in Portadown, Co Armagh, “could be catastrophic” for Northern Ireland.

The PSNI is the “shock absorber” when society fractures, he told members of the oversight body.

As the standoff enters its fifth day, talks aimed at resolving the stalemate were continuing on Thursday.

Central to the residents’ case at the Court of Appeal is a PSNI submission to the Parades Commission before the body determined last Friday the march could proceed.

A meeting between residents and Bryant, who has been involved in discussions with the Orange Order and Garvaghy Road residents since Monday, was due to take place on Thursday night.

A delegation, led by the group’s spokesman Breandán Mac Cionnaith and solicitor Darragh Mackin left Portadown to travel to Hillsborough Castle at 5.15pm, but returned a short time later with the meeting understood to have been rescheduled for 8pm. Mac Cionnaith said the group’s position had not changed.

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On his return, he met the Dundalk folk band The Mary Wallopers, who performed on Garvaghy Road on Thursday.

Addressing supporters before leaving for the initial meeting, Mac Cionnaith said they had only been informed a short while ago.

“I don’t know what time we’ll get back from there yet tonight, it might be possible for us to brief you at that time, but it could be 10pm, it could be 12 o’clock.

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“No matter what you hear, our position remains the same. There is no change in our position so hopefully we’ll get tonight over and there isn’t far to go.”

During Thursday’s Policing Board meeting, Boutcher said there will be “consequences” for those who blocked the Garvaghy Road last Sunday.

Northern Ireland First Minister Michelle O’Neill and Sinn Féin president Mary Lou McDonald were among those who stood with thousands of protesters before the planned parade.

Investigations into lawbreaking are “well under way” and will be “expedited”, Boutcher told board members.

Despite the “challenges” of the security operation, there has been no disorder in what he described as a “wickedly difficult” situation for officers.

“No one’s been injured … We’ve kept things calm, and we’ve created a space to try to resolve this,” Boutcher added.

The visible policing presence has since reduced in Portadown but the situation remained “challenging and complex”, members were told.

Boutcher said the cost of the policing operation has been £3 million so far, but warned of the consequences and cost “if they get it wrong”.

Earlier this week, Portadown Orange Order members called for the Chief Constable to resign over his handling of the standoff.

Boutcher said his aim is to facilitate the Parades Commission ruling “but in a proportionate and safe way”.

Members of the Orange Order are blocked by PSNI officers from marching down the Garvaghy Road in Portadown on Sunday. Photograph: Peter Morrison/PA WireMembers of the Orange Order are blocked by PSNI officers from marching down the Garvaghy Road in Portadown on Sunday. Photograph: Peter Morrison/PA Wire

“We are not back in 1997. We are not expected, and nor will we, force members of the Orange Order – many of whom are of a certain age – through a hostile crowd, which will be unsafe and will be disproportionate, and where the wider consequences for Northern Ireland could be catastrophic.

“The parade could not safely be facilitated on Sunday 27th of September, because of an unnotified protest that blocked the route. Officers repeatedly engaged with those involved and issued warnings.

“We considered a range of options, but assessed that the use of force required to clear the road risked serious harm and an escalation into disorder. That would not have been proportionate.

“The determination does not mean that the PSNI will move down the Garvaghy Road with force.”

The policing board is also investigating whether Sinn Féin board member Deirdre Hargey has breached the board’s code of conduct by allegedly taking part in a protest on the Garvaghy Road. The board’s chairman, Brendan Mullan, said that, following complaints, he has instigated proceedings to investigate the matter.

Jamie Bryson, a legal adviser for Portadown’s Orangemen, on Wednesday night said they were “not doing any deal” surrounding their contentious plan to march down Garvaghy Road. DUP MP Carla Lockhart said Orangemen would not accept any deal on the Drumcree dispute that saw them “walk away” from their right to parade down the Garvaghy Road.

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The standoff was raised in the Dáil on Thursday, where Sinn Féin’s David Cullinane warned that the controversy could “place at risk the accommodations that have developed around Orange Order marches across the North”.

Tánaiste Simon Harris said “this isn’t simply a green versus orange issue. It’s actually an issue between whether people want to go forwards or backwards.”

Earlier, Minister for Foreign Affairs Helen McEntee said “legally, the situation is that the Government has no remit or role in parading”. She said she was “very conscious of that” but had engaged with Bryant and others to try to find a solution.

Earlier, at the launch of Sinn Féin’s alternative budget, McDonald wished the continuing talks “fair speed and fair wind”. She said the “answer to this is to make absolutely clear that there will be no Orange march on the Garvaghy Road.

“If the talks can arrive at that, that’s great”.