Northern Ireland's economy will take a major hit from the collapse of Flybe with the tourism sector likely to feel the first effects, it has been warned.
Flybe ceased operations after going into administration on Wednesday night after prolonged trading difficulties.
For George Best Belfast City Airport, that has meant the loss of 80% of its flights - routes to 14 destinations like London City, Glasgow, Manchester, Birmingham and Southampton.
And trade union GMB warned that, along with seven other small airports around the UK, the collapse of Flybe has left Belfast City Airport at risk of closure.
Nadine Houghton, GMB national officer, said: "GMB is calling on the Government to step in and protect the regional airports. These hubs are vital parts of the UK economic infrastructure that communities and regional economies rely on. Without them economic disparities will widen, but now they face closure.
"Those workers directly affected by the collapse of Flybe and in the supply-chain need financial support to prevent hardship and protect livelihoods.
"We urgently need subsidies for socially necessary routes, funding for transport links and support for local authorities who want to develop airport plans. We will be working with our members and employers to ensure our jobs are protected during this dangerous moment for regional aviation."
But there was a glimmer of hope for some travellers at least, as two routes were rescued by Scottish airline Loganair.
It is taking over the Inverness and Aberdeen services.
However, there were no indications yesterday of any of the other routes being snapped up. But easyJet, Ryanair, British Airways and Aer Lingus Regional are possibilities for some of the most profitable routes, such as London, Glasgow, Birmingham and Manchester.
If we don't have air access from Great Britain - our largest market for tourism - the obvious downturn will be there to seeAndrew Webb, chief economist, Grant Thornton
EasyJet said: "It is too early to evaluate any future opportunities and right now our focus is to see how we can assist any Flybe passengers and staff with their travel arrangements."
Aer Lingus said "it will continue to evaluate capacity", while British Airways said its main focus for now was on getting stranded passengers home.
"We're offering special fares to customers that are left without flights following the Flybe announcement, and we'll bring any stranded members of Flybe staff home for free," the airline said.
British Airways and Aer Lingus, which are both owned by IAG, fly from Belfast City Airport.
While easyJet has its base at Belfast International, it previously trialled a Belfast City to London Luton route.
Frequent business users of at least one route indicated that they'd received assurances a new operator would be found.
Andrew Webb, chief economist at business advisory firm Grant Thornton, insisted restoring the majority if not all of the routes would be crucial to the economy here.
"Air connectivity is so crucial to business investment, to tourism," he said. "For example, the hotel sector has made a big bet in the last few years by investing £0.5bn in new stock, and it needs people for that stock.
"If we don't have air access from Great Britain - our largest market for tourism - the obvious downturn will be there to see."
Belfast City Airport chief executive Brian Ambrose said he was confident the slots would be filled.
In my view it's unlikely that the entire network would be taken up, and certainly not in the short-term. I'd predict you'd have half back within a year, then the rest will be a challengeAndrew Myers, industry expert
"We are confident that in the coming days and weeks we can start to announce replacement airlines coming in to operate those routes while being sensitive to the fact that a lot of people will be finding today very difficult," he added.
Economy Minister Diane Dodds said it was a difficult day for employees of Flybe but that she had already been talking to the airport about the routes being picked up again. "I have been speaking over a number of weeks with the airport. They are confident that these routes are strong, viable and profitable and that other airlines will want to come in and use the routes.
"That will be good for Northern Ireland because connectivity to Great Britain, our biggest market, is absolutely vital."
But industry expert Andrew Myers said he was pessimistic about the routes being filled in the near future, particularly as many airlines are in crisis mode at the minute as they struggle with the impact of coronavirus on bookings.
Mr Myers said: "It's difficult to say at the moment how many routes will be picked up. The impacts of the coronavirus on travel aren't full understood, or the length of its impact.
"But airlines will look at these routes on a case by case basis, so I would expect to see Birmingham, Glasgow and Edinburgh served quite quickly by a new carrier. I would imagine easyJet will come forward, and we've already had Loganair. Eastern Airways might pick up one or two, but after that, you're really struggling.
"In my view it's unlikely that the entire network would be taken up, and certainly not in the short-term. I'd predict you'd have half back within a year, then the rest will be a challenge."
Ulster Unionist peer and former Stormont Economy Minister Lord Empey said the Government should consider short-term public service obligations (PSOs) - a form of support for non-profitable routes - to buoy up connectivity.
But he accepted times were tough in the industry.
"I hope that some airlines will begin to fill the gap, but we are in the middle of a perfect storm for the airline industry with the coronavirus impacting bookings and hitting all of them," he added.