Lorna Slater said if an exemption from the Internal Markets Act was not confirmed then the Scottish government would have to decide on its future.

The BBC understands the UK is unlikely to reach a decision in this timeframe.

Ms Slater told the Scottish Grocers' Federation that a lack of response could render the scheme "unviable".

The scheme, which is aimed at increasing the number of single-use drinks bottle and cans that are recycled, was due to start in August.

It will now not launch until March of next year.

Ms Slater - the Scottish Green co-leader who has been driving the scheme - said she was still working closely with the UK to make the launch happen.

She said she would know "one way or the other" by the end of the month.

The scheme requires Westminster to grant an exemption to the UK-wide Internal Market Act, given its possible implications for business elsewhere in the UK.

It has faced opposition from many small breweries and distillers.

Bottles and cans could be returned over the counter or through reverse vending machines

It will see 20p added to the price of a single-use drinks container in Scotland, which will be refunded to people who return the container.

Some retailers will accept returns over the counter while larger stores, shopping centres and community hubs will operate automated receiving points known as reverse vending machines.

Circularity Scotland, a not-for-profit company established to administer the scheme, said the ongoing uncertainty was causing a crisis for its future.

Its chief executive David Harris, said: "We have written to the prime minister and first minister to stress the growing urgency around this and make it clear that many millions of pounds and hundreds of jobs are at risk if there is further delay.

"Business and industry have come together to make this a reality, without any cost to the taxpayer.

"However, we now find ourselves caught in a policy vacuum which calls the very future of delivering successful deposit return schemes in the UK into question."

The Scottish Conservatives accused Lorna Slater of "trying to pass the buck" to Westminster.

MSP Maurice Golden said: "When major retailers are calling for a UK-wide approach and smaller ones are still waiting for information about how it will work, she's effectively trying to blackmail the UK government into bailing her out."