Scotland’s controversial deposit return scheme could be axed by the end of the month if the programme is not given the green light by the UK Government, according to the minister responsible for its delivery.

Lorna Slater said First Minister Humza Yousaf had written to Prime Minister Rishi Sunak to set a deadline for a decision on an exemption to the Internal Market Act (IMA), without which, the flagship recycling plans cannot go ahead.

The Greens’ minister told attendees at the Scottish Grocers’ Federation conference that a lack of response could mean the scheme is “unviable” and would have to be shelved until a later date.

Circular economy minister Ms Slater said she had hoped to receive the exemption by April 17, but Scottish ministers are yet to be granted clearance for its launch – which has already been pushed back from August 2023 to March 2024.

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However, Ms Slater admitted “uncertainty” over when the rollout would be approved could see it withdrawn altogether in its current state.

“The First Minister wrote to the Prime Minister last week, setting a deadline at the end of May,” she told the conference.

“So if we haven’t heard from them by the end of May, because of the concerns around the viability of the scheme going forward, we will have to make a proactive decision at that point as to whether the scene is viable or not to move forward.

“I can’t say exactly how that’s going to fall out. We’re still working very closely with the UK government to make that happen.

“You know, this is now at as high as you can go, this is the First Minister talking directly to the Prime Minister about this. It’s at the highest possible level. So I’m hoping to find out urgently.”

READ MORE: Lorna Slater blames UK ministers for deposit return scheme delay

She added: “By the end of May, we’ll know one way or another.”

Under the scheme a 20p deposit would be added to all single-use drinks containers made of plastic, metal or glass. The deposit would apply to both alcoholic and soft drinks.

Consumers would then get their money back by returning the container to retailers and hospitality premises that sell such single-use products to take away.

Retailers will accept items over the counter, while larger stores, shopping centres and community hubs will operate automated receiving points known as reverse vending machines (RVMs).

The DRS would have been the first of its kind in the UK but businesses in Scotland have expressed concerns over its rollout.

Industry figures argue it would impose potentially fatal costs on their business and create a trade barrier between England and Scotland, but environmental campaigners say it will cut carbon emissions and reduce litter.

The scheme also came under close scrutiny during the SNP leadership contest with candidate Kate Forbes, the former finance secretary, saying it would create 'economic carnage' for businesses.

Launching her official leadership campaign at the Cairngorm Brewery in Aviemore on February 27, Ms Forbes said the scheme was “well intentioned”, but stressed significant concerns had emerged about its execution.

She told journalists: “It’s execution is leaving businesses like [the Cairngorm Brewery] fearing for their future. It’s leaving businesses like this fearing the economic carnage it will cause if the timetable continues as planned right now.

“The idea of having a deposit return scheme is sound, but we cannot have a scheme that is well intentioned, but fails to achieve its aims and causes economic carnage in the process.”

SNP MSP Fergus Ewing called repeatedly for the scheme to be axed describing it as a 'green poll tax'.

Responding to the development that the DRS may not go ahead, David Harris, chief executive of Circularity Scotland, the organisation set up to run the scheme, warned there was “growing urgency” to find a solution to the current impasse, with millions of pounds and hundreds of jobs at risk.

“As Circularity Scotland is a not-for-profit business reliant on fees from producers to operate, the delay in the scheme going live forces us to review our business plan and provide clarity to our banks and those producers who are providing our funding before the scheme goes live,” he said.

Scottish Conservative MSP Maurice Golden said: “It defies belief that, after her staggering mishandling of this scheme has led to its delay, Lorna Slater should still be trying to pass the buck to Westminster.

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“When major retailers are calling for a UK-wide approach and smaller ones are still waiting for information about how it will work, and whether they will be compensated for the huge costs she has landed them with, she’s effectively trying to blackmail the UK Government into bailing her out.

“The reality is that her version of DRS had to be paused because there were so many unanswered questions and legitimate concerns. She and the SNP-Green Government should be accepting responsibility, making amends, and completely rethinking so that we can have a scheme that actually delivers.”

A UK Government spokeswoman said: "UK Government ministers received a formal request for a UKIM Act exclusion for the Scottish Government’s Deposit Return Scheme on March 6 2023.

“The Scottish Government has since been reviewing and paused the scheme until March 2024 to allow it more time to address concerns raised by businesses. It therefore hasn't been possible yet for us to fully assess the impacts of the exclusion request on cross-UK trade, firms and consumers.

“We will continue to engage with the Scottish Government to realise our shared ambition to improve the environment while meeting the needs of consumers and businesses across the UK.”