The Portrush Sons Of Ulster band voted to reject a request to postpone their July 19 event.
More than 60 bands and 2,000 participants are set to take to the streets of the town alongside spectators, according to an application lodged with the Parades Commission.
The event is due to begin at 8.15pm, shortly after the end of play on day three of The Open, leading to fears that thousands of golf fans will be stuck in congestion delays as they attempt to leave.
Organisers of the golf tournament — taking place here for only the third time in its history — said they fear ‘the potential logistical impact’ of the clash.
The Coleraine Chronicle reported that, separately, the band was offered a ‘substantial’ financial incentive to postpone the parade but band members voted to reject the offer last week.
A spokesman for tournament organisers the R&A told the Belfast Telegraph they have concerns.
“The return of The Open will be the biggest sporting event to be held in Northern Ireland. We recognise that we are guests in the towns and communities that we visit and fully respect the culture of our hosts,” they said.
“We also want to do all that we can to ensure that the fans enjoy an amazing experience of Portrush.
“We are concerned about the potential logistical impact of other events taking place on the Saturday evening of the Championship and continue to work with our public agency partners to explore potential mitigations to ensure fans can get home smoothly following the end of play that day.
“We will continue to plan as far as we can to minimise any disruption.”
Local PUP councillor Russell Watton said he supports the band in their decision not to postpone the parade.
“They have been marching for 43 years, the Open is only here now,” he said.
“This is a tradition that a lot of people look forward to every year and I respect the band for holding their ground.”
Sports Journalist Adam McKendry plays a round of golf at Royal Portrush
Mr Watton said the parade is the busiest day in Portrush’s calendar.
“This is the event of the year for businesses in Portrush, it’s bigger than the raft race and the North West 200,” he added.
“We have people coming from all over — Fermanagh, South Down, all over. People celebrate their local parades over the Twelfth and then they come down to Portrush for the weekend. It’s a weekend for the wife and kids — it’s something for everyone to enjoy.”
Mr Watton said he understood the R&A’s concern but feels congestion will be manageable, adding: “Congestion can be an issue but Portrush will be busy as it is.”
According to the Parades Commission 64 bands are registered to attend.
They will gather at Sandhill Drive before setting off at 8.15pm into Station Square via Eglinton street, down Kerr Street towards the harbour and back to the start point via Main Street, Causeway Street, Victoria Street and Dunluce Avenue.
The parade is due to finish by 11pm.
More than 250,000 people are expected to attend The Open next month.