McIlroy mania is set to hit the sold out Open at Royal Portrush with record crowds for the biggest sporting event in Northern Ireland history. And the R&A chief executive has claimed the new Masters champion has “unfinished business” at his home Major after missing the cut here in 2019. All 278,00 tickets have been sold - an increase of 41,000 - after over one million people entered the public ballot for the 153rd Open. It will be largest attendance for an Open after the 290,000 who went to the 2022 Open at St Andrews . “We have huge demand for the Open Championship, something we're very proud of,” said Mark Darbon. “I think his (McIlroy’s) win is brilliant for the sport of golf , not just our own championship. It was an amazing emotional win as many of you witnessed and we're delighted to see Rory McIlroy’s name in the history books. “I think it just gives us a great run into our event. The 153rd Open will be the largest sporting event ever held in Northern Ireland.” The 148th Open returned to Ulster after a 68-year wait in 2019 but McIlroy took a quadruple-bogey eight on the first hole on his way to missing the cut. He will return to Antrim’s coast in July as only one of six men to ever complete the career Grand Slam with his thrilling playoff win at the Masters . “I've written to him recently to congratulate him,” added Darbon. “It's been a real privilege as part of this role getting to meet some of the elite players in our game and I've spent a little bit of time with Rory over the last few months. We know he's super excited to return here, he has some unfinished business on this course, so he'll be very focused on performance and we look forward to welcoming him.” The Open is back in Ulster after six years but there is still no prospect of staging the event at Donald Trump's Turnberry. The Ayrshire course last held the Open in 2009 but the US President bought Turnberry in 2014 and overstated the hosting of the 2015 Women’s British Open by arriving in his helicopter. Darbon, the former CEO of Northampton Saints, said: “Turnberry is a wonderful golf course, and I think some of the recent improvements there have made it even better. It's a course we'd love to return to at some point. But where we have some challenges is around logistical and commercial challenges. “I think the last time we were there in 2009, we had just over 120,000 people. We just said we're going to have close to 280,000 here this summer. “That's really important for us because not only do we want to showcase this wonderful championship to as many people as possible, but it's important for us in terms of our commercial model because everything we generate from The Open we then reinvest back into the game all around the world . We've got a few challenges at Turnberry. The road, rail, and accommodation infrastructure presents some challenges if we wish to scale our operation there.” But asked about the Trump Factor, Darbon added: “I think the key issue for us at the moment is these logistical and commercial challenges. We're trying to explore ways to get around those and to mitigate for the future. Of course, when it comes to a championship like this, we also want the focus to be on the golf. So that's a factor too. Royal Birkdale will host next year and St Andrews again in 2027. McIlroy, who returned home to Belfast last weekend, is back in action on the PGA Tour this week at the Zurich Classic of New Orleans where he will defend the title alongside 2019 Open winner Shane Lowry.