Greens minister Lorna Slater has been branded “spectacularly unhelpful” after opponents claimed she has not explained why a controversial company behind the under-fire deposit return scheme (DRS) is exempt from scrutiny.

Scottish LibDems climate spokesperson, Liam McArthur, has vented his frustration at Ms Slater after he criticised the company, set up by ministers to roll out the troubled recycling scheme, being allowed to “sit above public questioning”.

Under the Scottish Government proposals, the 20p deposit on cans and bottles will be returned when customers take empty containers back, with Ms Slater saying it would increase recycling rates for such items to 90%.

Circularity Scotland, set up to administer the delayed policy, is exempt from Freedom of Information requests, while the salaries of bosses are kept secret.

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Ms Slater said it would not be possible to make changed because Circularity Scotland is “privately operated”.

Despite the refusal to open up the company to scrutiny, former first minister Nicola Sturgeon told Tory MSP Maurice Golden she would consider extending Freedom of Information laws by issuing a section five, to cover the company.

But Ms Slater has said that “it would not be appropriate” to do so.

The finances of Circularity Scotland have remained a mystery, with the publicly-owned Scottish National Investment Bank, refusing to tell The Herald how much public finance the company has received due to it being a private firm.

Circularity Scotland was intended to represent the drinks industry as part of plans to roll out the DRS and its membership includes multi-national companies, Coca Cola, Diageo and Danone, as well as major supermarkets.

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Mr McArthur has criticised Ms Slater after she refused to say whether alternative models of governance have been considered for Circularity Scotland.

She said that it was agreed for the DRS to be “a privately operated scheme” which is “in line with international best practice”.

Ms Slater said: “Just like similar schemes around the world, Scotland’s Deposit Return Scheme (DRS) is being delivered and funded by industry.

“It is for them to determine the appropriate manner in which to meet their obligations under the regulations, including whether or not to establish a private company to act as a scheme administrator.

“Given that it is already standard that private companies are not covered by Freedom of Information legislation, and producers themselves formed and administer Circularity Scotland, the Scottish Government does not consider an assessment of any potential impact on relations between the DRS administrator and producers where Circularity Scotland is not subject to Freedom of Information legislation to be necessary.”

But Mr McArthur said the response from Ms Slater still needs clarity.

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He said: “We are no further forward in understanding why Circularity Scotland was set up like this, who took the decision and whether alternative options were considered.

“The public and parliamentarians should not have to rely on leaked reports to find out the Circularity Scotland chief executive is being paid £300,000 per year. Nor should a firm delivering a service that will affect all of our lives be allowed to keep its business under wraps.

“It might appeal to this SNP-Green Government to have their new administrative body sit above public questioning but it’s terrible for transparent and effective governance.”

He added: “Meanwhile, evading scrutiny once again with yet more spectacularly unhelpful answers may feel like a joke to the Minister, but businesses and consumers in Scotland are unlikely to find this behaviour so amusing.

“At the moment, the main thing getting recycled seems to be ministerial excuses.”

A Scottish Government spokesman said: “Scotland’s deposit return scheme will be a major part of our efforts to reduce littering, cut emissions, and increase recycling.

“In line with the polluter pays principle, and just like many successful schemes around the world, the scheme is being delivered and funded by industry.

"This decision was taken following extensive public consultation and was approved by the Scottish Parliament in 2020. This means that Circularity Scotland, the scheme administrator, is a not-for-profit business organisation formed by industry, and is not covered by FOI legislation.

"However, they have invited MSPs to engage with them and ask any questions of them that they may have.”