The Scottish Greens have proposed a railcard that would give people aged 31 to 49 a third off train fares in Scotland, funded by a levy on frequent flyers.
Party co-leader Ross Greer announced the proposal at the Scottish Greens’ conference at Eden Court in Inverness.
The party said the proposed frequent flyer levy would not apply to lifeline air services supporting remote and island communities.
An estimate by the Scottish Trades Union Congress suggested a frequent flyer levy in Scotland could raise around £50 million a year.
Mr Greer said: “This weekend we are proposing a Frequent Flyer Levy for those who get the plane like the rest of us get the bus.
“Regular business flights within the UK are literally fuelling climate breakdown. They should be paying far more than families going on holiday once a year.
“While bankers fly back and forth between Edinburgh and Canary Wharf multiple times a week, millions of people are working every hour they can get and still struggling to get by.
“We have a whole generation who came into adulthood during and after the 2008 financial crash.
“Millennials who too often still can’t afford a deposit for a home, still can’t afford to start a family, still can’t get graduate jobs. They are also the only people currently paying full price for their train tickets
“Everyone else can get a discount or railcard. So today I can announce that Green MSPs would use the money from taxing frequent flyers to deliver a millennial railcard, offering one third off train fares for people in their 30s and 40s.”