The Scottish Government’s 2021 ban on landfill waste is off target and will rely on exporting rubbish elsewhere, according to an official report.

It found the fallout from the ban could cost the Scottish economy more than £1 billion.

Legislation banning biodegradable municipal waste being sent to landfill comes into force in 2021 but the Scottish Government Waste Markets Study predicted insufficient capacity to meet the expected level of need.

Of Scotland’s councils, 14 had solutions in place, three had a long-term plan but no interim solution and six vice versa, while nine had no alternative arrangements at all.

This is despite the “significant notice” given of the planned ban, announced in 2012.

If recycling targets are met, the shortfall of treatment capacity in Scotland compared to waste produced is predicted to be just over one million tonnes a year, falling to 90,000 tonnes by 2035.

The report states: “Excluding consideration of waste minimisation and recycling, the ban will result in significant economic costs to Scotland due to the need to export an increased amount of residual waste – whether as an interim solution until new thermal treatment capacity comes online, or as a long-term solution.

“This has the effect of exporting revenue to English or continental landfill or treatment providers.”

Researchers modelled the likely costs, which ranged from £414 million to £1.156 billion.

Opposition politicians criticised the Scottish Government’s handling of the ban.

Scottish Liberal Democrat leader Willie Rennie said: “It would make a mockery of the law if the SNP’s solution to meeting their own landfill ban is to ship it to England or abroad.

“Ministers are relying on a loophole so big you could drive a rubbish truck through it.”

Scottish Conservative environment spokesman Maurice Golden said the target was an “SNP gimmick”.

He said: “The Nationalists made a daft prediction without either the ability or willingness to achieve it.

“This damning report shows that their target is wildly off-schedule.

“And what’s even more worrying is the cost to Scotland’s economy of this catastrophic misjudgment could be more than £1 billion.”

Scottish Labour’s environment spokeswoman Claudia Beamish, said: “This is another broken promise from the SNP.

“Despite warm words from ministers, the Government’s own research shows it is set to miss its target to eliminate biodegradable waste going to landfill from our councils.

“It is simply not enough for ministers in St Andrew’s House to set targets, they need to help councils make this change a reality by giving them the appropriate resources.”

A Scottish Government spokeswoman said: “The Scottish Government is committed to ending the practice of sending biodegradable municipal waste to landfill.

“This will contribute to progress on climate change targets and increase incentives to deal with waste in a more sustainable way.”

“We have been working closely with local authorities and commercial bodies to assess and support progress towards implementing the ban.

“Our focus now is on working with authorities who do not yet have a solution in place to identify ways, such as collaborative procurement and improved recycling, in which they can comply with the ban.”