Plans to axe aviation tax are a "giveaway to Scotland's wealthiest households and corporations", according to campaigners.

About 70% of the country's richest households will benefits from the Scottish Government's plans, compared to 30% of the poorest, they claim.

Air departure tax is expected to come into force from April 2018, replacing air passenger duty.

Campaigners Fellow Travellers, who are are opposed to the plans, say businesses and wealthy leisure travellers who fly frequently will benefit the most.

They estimate that the average saving per journey will be £54 on a luxury jet, £20 in first class and £8 in economy.

Their report, which was published by the Scottish Greens, says halving the tax will lead to £189m in lost revenue for Scotland by 2021/22.

Co-author Leo Murray said he hoped the "woefully under-informed" policy would be reconsidered.

He said: "Our analysis shows clearly that cutting and then scrapping taxes on air travel will primarily reward corporations and Scotland's richest households for choices that will set us back in the fight against climate change, at the same time as damaging domestic tourism and the rail sector.

"The single biggest outcome of this change, if it is made, will be more wealthy Scots flying to London to spend their money there."

A Scottish Government spokesman said it was committed to a "progressive, fairer tax system" and its air tax plans are a "fundamental component to improving Scotland's international connectivity and providing a real boost to our economy".

He added: "UK air passenger duty is the most expensive tax of its kind in Europe and one of the highest in the world and continues to act as a barrier to Scotland's ability to secure new direct international services and maintain existing ones."