Concern is growing in the Highlands that the level of air service between Inverness and Gatwick will be threatened by Flybe's decision to sell its slots at the London airport to easyJet for £20 million.

There are now calls for urgent action to safeguard the thrice-daily flights to and from Gatwick.

There is particular demand to keep those leaving Inverness at 7am with the return flight not departing London until 7.20pm, which allow business users a full day in London without the need for an overnight stay.

There are fears easyJet may use some of these slots for more lucrative European routes.

Flybe chairman Jim French said prospects at Gatwick were not encouraging. He said: "We have to accept the ugly reality that Gatwick simply doesn't want smaller, regional aircraft at their airport."

He pointed to the absence of a regional aviation strategy and the UK Government's "penalistic and ludicrous" policy of charging air passenger duty on both legs of a domestic flight.

He said: "I'm afraid it is inevitable that high-frequency services from the UK's regions will ultimately be squeezed out of Gatwick, as they have been from Heathrow."

Flybe's sale of its Gatwick landing and take-off rights is part of a cost-cutting programme at the low-cost airline, including the axing of 600 jobs and pilots agreeing to a 5% pay cut.

Civic and business leaders in the Highlands have feared a further reduction of service to London ever since British Airways pulled out of its three-times-a-day service to Heathrow in November 1997, leaving British Regional Airlines to operate a service to Gatwick with smaller planes.

EasyJet will not take over the slots until the end of March next year and has said it will consider maintaining some of Flybe's Inverness-to-Gatwick flights.

EasyJet already flies on the route but its first flight south during the week is not until 1.45pm, arriving at Gatwick at 3.20pm. It also flies to Luton, leaving at 11.25am.

Mr French added: "EasyJet is committed to continuing to provide Inverness with easy and affordable links to London. EasyJet already provides up to three daily flights to Gatwick and Luton airports."

Chief Secretary to the Treasury Danny Alexander will meet local stakeholders in Inverness today to discuss the way forward.

He said: "These connections are vital for the Highland economy, and this announcement will clearly cause uncertainty for local businesses and the staff involved."

He said astronomical increases in landing charges at Gatwick had hit Flybe hard. However, the SNP pointed to the Air Passenger Duty (APD), which is controlled by the UK Government.

Fergus Ewing, MSP for Inverness and Nairn, said the managing director of Flybe had said "the punitive levels" of APD imposed on UK domestic airlines had meant not one of Flybe's services to Gatwick has returned a profit over the last year.

The Minister for Energy, Enterprise and Tourism added: "The loss of these services would be a hammer blow for the Highlands. The Inverness Flybe service is the one used by Danny Alexander to get to Westminster – and now it is being withdrawn, in part because APD is too high."

Highland Council leader Drew Hendry (SNP) said he was writing to Easyjet to seek a meeting. He said: "These connections are of immense importance to our economy. The slots are crucial for business connections, tourism and inward investment."