THE Scottish Government has been urged to back a "frequent flyer levy," as ministers announced the latest steps towards replacing air passenger duty (APD) in Scotland.

Green Party leader Patrick Harvie has outlined a plan to exempt holidaymakers or other passengers who only take a single return flight each year from the tax.

However, he said charges for other travellers should rise with each extra flight they took.

He challenged the government to maintain, or raise, overall taxation on airlines - without putting air travel beyond all but a few - saying it was essential to limit greenhouse gas emissions.

The MSP made the call as John Swinney, the Deputy First Minister and Finance Secretary, repeated his pledge to halve APD as a first step towards scrapping it altogether.

During a visit to Edinburgh Airport, he chaired a new group made up of aviation, environmental and tax experts, set up to discuss how an alternative to APD should be configured when it is devolved to the Scottish Government.

APD on flights from Scotland raises about £230million per year.

It is set to become the responsibility of the Scottish Government following the Smith Agreement on extending devolution.

At present it is passed on to passengers through ticket prices and ranges from £13 to £142 for most flyers, depending on whether they are travelling long or short haul and in economy or standard class.

Higher rates apply to large private jets.

Mr Swinney has pledged to halve the present burden by 2021, under a new Scottish APD, with a view to abolishing the levy altogether "when public finances allow".

He has been backed by the aviation industry, which produced a report claiming a 50 per cent reduction in APD would boost the Scottish economy by £1billion and create 4000 jobs.

Mr Harvie said scrapping ADP would increase greenhouse gas emissions from planes by 60,0000 tonnes, making it almost impossible for the Scottish Government to meet its climate change targets.

He said the targets - missed each year since they were introduced in 2009 - had already been exceeded by 10,000 tonnes.

He said: "If the Scottish Government is remotely serious about its climate change commitments, it needs a replacement tax that will cut pollution without making aviation unaffordable for everyone but the wealthiest.

"The most positive idea yet proposed is a frequent flyer levy, under which people would pay nothing if they took one return flight a year, but after that the levy would rise with each extra flight."

He added: "This would acknowledge the enormous environmental impact of aviation, while recognising that most of the growth in flights isn't due to people taking an annual family holiday - it's due to a wealthy jet-set minority, who are coming to treat air travel as casually as hailing a taxi."

Mr Swinney said he wanted Scotland's airports to grow in order to boost the economy.

Welcoming the new expert group, he said: "The forum and this autumn’s policy consultation allow us to take the next step and begin the process of designing and developing a Scottish APD to help deliver our objective of sustainable economic growth."

Sophie Dekkers, easyJet’s UK director, said: "Now that powers over APD are being devolved to Scotland, and as Scotland’s biggest airline, we are pleased to be working with the Scottish Government to halve and then abolish the tax.

"When APD is halved passengers in Scotland will quickly feel the benefit, with easyJet and other airlines adding more services to existing destinations and launching flights to new destinations from Scotland.?"