COVID has transported Scotland's airport passenger numbers back to the 1970s, MPs have heard.

The level of travellers at Glasgow Airport dropped to 2million in 2021, the Scottish Affairs Committee was told. Brian McClean, director of communications and sustainability at owners AGS Airports, said that level hasn't been seen since 1973 and marks a huge fall since on the 9m total recorded in 2019.

For Aberdeen, passenger numbers slipped from 3m in 2019 to 1.1m last year.

McClean told MPs: "This has absolutely set us back decades when it comes to loss of passengers and loss of connectivity."

The cross-party Westminster committee was taking evidence from three airport chiefs as part of an inquiry into the sector in Scotland.

Bosses criticised health and travel restrictions, with Edinburgh Airport boss Gordon Dewar claiming the industry had been "legislated out of business".

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And the trio, including Highlands and Islands Airports Limited (HIAL) managing director Inglis Lyon, said the lack of a four-nations approach had made things tougher.

On the impact of restrictions on international journeys, Dewar said: "If you consider the prospect of somebody coming as an international visitor to Scotland, why would you?

"Restrictions are far, far harder, and they have been through pandemic here, here in Scotland in particular than they have been anywhere else. So it's a deeply unattractive place to come whether that's for study or tourism."

He said: "At the bottom of the curve, we were down at less than 1% of pre-pandemic levels of demand, which is actually worse than being closed because you've got all the costs of being open but very little revenue to support that."

Dewar also criticised the Scottish Government's provision of a loan to Glasgow Prestwick Airport, saying it "fundamentally skews what should be a competitive and fair playing field".

His operation has suffered losses in excess of £100m, he said, and taken on debt while facing a fragile recovery: "We're very, very far away from normal levels of demand, and as importantly, normal levels of confidence about the future."

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MPs heard that Edinburgh Airports has made 250 staff redundant, with as many as 2000 posts lost across the campus between all employers. Glasgow has also suffered around 2000 losses, with around 400 jobs gone in Aberdeen.

On the outlook for recovery, McClean called for a new destination marketing drive involving government agencies. He said: "When you're in a crisis your long term view diminishes and you only focus on dealing with what's immediately ahead of you, so we do need that longer term.

"It's going to take us years to get back to pre pandemic levels and 2025, 2026 at the earliest. And that's because as we come through this, they're going to be less airlines with less aircraft, but there's going to be the same number of airports all trying to attract these airlines back into our, into our bases and our airports."

Dewar accused Scottish ministers of "talking down and asking people not to make use of" relaxations of restrictions when a four-nation alignment has been in place.

Lyon, whose operation takes 50% of its revenue funding from the Scottish Government and has seen no Covid-related job losses, said the differences in travel rules between Scotland and other parts of the UK have at times been "very difficult to explain".

Meanwhile, McClean said airports had faced "the worst of both worlds" when travellers barred from reaching certain countries under Scottish rules could go to Manchester and fly from there. He said: "There was no public health benefit there because people were still travelling."

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Lyon said passenger confidence "falls off a cliff" with every announcement of further restrictions.

On the importance of retaining links between Inverness and London Heathrow, he said: "These things hang by a thread when the industry is under the pressure that it's under, both in terms of aircraft availability, in terms of profitability, in terms of eyewatering losses of the last two years.

"Marginal routes like that come under a great deal of pressure."