Budget airline Ryanair is to close its base at Glasgow Airport.
The number of winter routes operated from Glasgow will be reduced from 17 to three, with five being transferred to Edinburgh.
The airline will also cut its routes from Prestwick from ten to eight.
However, Edinburgh’s will increase from 35 to 45.
Chief commercial officer David O’Brien said Edinburgh has a stronger “inbound component” than Glasgow with Ryanair flights.
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He said 300 jobs could be lost at Glasgow due to the move with a potential fall in around 500,000 passengers.
He added the decision was down to Air Passenger Duty (APD) for such flights not being halved from £13 to £6.50 per passenger as the Scottish Government had planned.
He also said Brexit was a threat to Scottish tourism and the airline industry.
Ryanair will only fly to Dublin, Krakow and Wroclaw from Glasgow in its winter 2018 schedule with its base at the airport closing and the one aircraft there moved elsewhere.
Many of the routes being cut are city-break type destinations rather than coastal holiday resorts.
The 45 routes from Edinburgh will include 11 new routes.
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Ryanair opened its base at Glasgow Airport in autumn 2014, one of several new bases opened across Europe that year.
At the time it said it remained committed to Prestwick Airport, continuing to offer flights from there.
Routes to Gran Canaria and Barcelona are being lost by Prestwick.
Mr O’Brien said these had been largely protected as they were popular Mediterranean holiday destinations.
However, the Glasgow cuts come despite Ryanair chief executive Michael O’Leary threatening to cut some of 13 new winter routes from Edinburgh if ministers did not follow through with halving air taxes.
The plan, involving replacing APD with a new Air Departure Tax (ADT), has been put on hold because of the need to get EU approval to continue an exemption for Inverness Airport.
The minority SNP government is also unlikely to have got it approved by MSPs because it has done a Budget deal with the Greens, who oppose cutting air taxes.
Describing itself as Europe’s first and largest low fares airline, Ryanair carries more than 130 million customers a year on more than 2,000 daily flights from 87 bases.
A spokesman for Glasgow Airport said: “We are bitterly disappointed at this decision by Ryanair which is not only damaging for Glasgow and wider Scottish connectivity, it will impact approximately 100 jobs locally. This is a result of the airline’s review of its single aircraft bases, however, we have been left in no doubt it is also a consequence of the Scottish Government’s inability to introduce its proposed 50 per cent cut in ADT.
“Despite clear and repeated warnings from both airports and airlines about the potential impact of this policy not being implemented, we are now faced with a stark scenario that includes the loss of 20 services and a significant number of jobs.
“This is the second example in as many months of an airline cutting capacity in Scotland because of the lack of movement on ADT.
“The reality is this capacity will be reallocated elsewhere in Europe to countries with more favourable aviation taxation policies to Scotland’s detriment.
“We cannot sit back and risk Scotland’s connectivity being further eroded. It is imperative there is immediate action on ADT.”
A Preswick Airport spokeswoman said: “Our winter schedule has 16 flights per week to eight destinations.”
This is a commercial decision for Ryanair, but we are delighted that we are seen as key to their operations in Scotland and that Ryanair is committed to continuing to operate from Prestwick.”