Irish low-cost carrier Ryanair is to build up Glasgow Prestwick International airport into a third hub and is planning to establish a fourth base somewhere in continental Europe.
The airline says it has decided to establish new hubs because of prohibitively high airport charges at its Dublin base, and warns that it plans to reduce capacity there unless airports operator Aer Rianta introduces a new payment regime.
Ryanair says it has no such concerns about its second hub at London Stansted, however, and adds that rather than calling a halt to further expansion there - as claimed in recent newspaper reports - it will add new services next summer.
The carrier's Prestwick plans have led it to sign a ten-year agreement with bus and train operator Stagecoach, which bought the airport earlier this year in its first foray into the aviation sector.
Ryanair already operates flights from Dublin and Stansted to Prestwick, and from 19 November it will begin a daily service to Beauvais north of Paris.
Further route expansion will see the carrier operate from Prestwick to a number of its existing destinations, with Brussels, Stockholm and Oslo likely to be added first, followed by destinations in southern France - possibly Toulouse/Carcassonne - and northern Italy, where Ryanair flies to Venice, Pisa and Rimini.
Ryanair finance director and company secretary, Howard Millar, says the airline has opted to build Prestwick into a mini-hub largely because the Scottish market is grossly under-served in terms of the number of direct continental destinations available.
However, Millar also concedes that Prestwick's generous charging scheme is a major factor in the move, contrasting the terms available from Stagecoach with the "ridiculously high" charges he says state-owned Aer Rianta demands at Dublin.
Stagecoach is also not planning to raise charges in response to the scrapping of duty-free sales within the Europe Union next year, since Prestwick handles more freight than passenger traffic and is not dependent on duty-free revenues.
"We have an issue here in Dublin in terms of charges and we have been lobbying Aer Rianta and the Irish Government for a new deal," he says. "Charges are already too high, and when duty-free goes the discount scheme ceases and we will be facing new charges.
"If that happens, there will be no new routes. There have been seven launched this year, and none of them were from Dublin either. There is huge demand for low-cost routes throughout Europe, but we are not prepared to launch them from Dublin if the costs are too high."
He adds: "We are not closing down Dublin, and we don't want to hand the network we have built up here over to another airline. But we will certainly reduce capacity out of Dublin in order to accommodate growth elsewhere."
Millar says that frequencies from Dublin may be cut back, while the five Boeing 737-800 aircraft that Ryanair will take next year will be based at Stansted rather than in Ireland. The new aircraft will be equipped to carry 189 passengers, whereas the 737-200s that will continue to operate Dublin routes carry only 130.
Millar says that Ryanair is also planning to establish a "fourth base", which will built up at one of its existing destinations in continental Europe. He adds that the airline is currently talking to a number of airports, and that it has no firm views about where the hub should be located.
"It depends who is able to offer the best deal," he says, adding that Beauvais "offers potential" and that Brussels Charleroi is a possibility, but also declining to rule out south European locations. "The plan is that there is no plan," he says.
Ryanair is meanwhile planning to launch services to several new destinations next summer, with some likely to be in 'new' countries. The carrier has previously said that it has agreed potential deals with at least 11 European airports and held discussions with 20 more.
Millar says several new services will be added at Stansted, while the potential of other UK airports - including Birmingham, Manchester and Luton - is also being examined.
Of Stansted, he says: "We are of the opinion that it still remains a very valuable place for new routes. The costs there are low compared to Dublin, and although we would like them to be lower we can live with them."
Millar says that Ryanair is unfazed by the decision by Belgium-based no-frills carrier Virgin Express to build up a presence at Shannon International airport in the west of Ireland. Though the carrier will operate flights to Stansted, he says that Virgin supremo Richard Branson has made it clear that he has no plans to challenge Ryanair on existing routes.