The Scottish Government was yesterday urged to issue an emergency statement on the controversial bottle-return scheme as a key deadline looms.
Producers risk being banned from selling their products in Scotland if they fail to sign up by tonight.
The Scottish Tories have called for a statement to clear up "unanswered" questions about the initiative.
The government said it would take a "pragmatic approach to implementation".
The deposit-return scheme (DRS), due to begin on August 16, will introduce additional 20p charges on drinks in cans or bottles, with the deposit returned when they are brought back for recycling.
Producers will have a legal responsibility for the collection and management of drinks containers.
'Potentially-catastrophic' costs
But industry figures have warned it could impose potentially-catastrophic costs on their businesses.
Circular Economy Minister Lorna Slater has said she is "actively considering" a one-year grace period for smaller businesses but has still urged them to register.
The BBC says all three SNP contenders to replace Nicola Sturgeon as first minister have raised concerns about the scheme in its current form.
The Scottish Conservatives have urged Ms Slater to halt the scheme pending an independent inquiry.
The party's chief whip, Alexander Burnett, has written to the Scottish Government's business manager, George Adam, requesting an emergency ministerial statement.
Tory MSP Maurice Golden said: "It should never have got to the stage where, on the eve of the deadline, key questions about the scheme remain unanswered - such as, will there be a grace period for small producers and, if so, what is a 'small producer'? But, astonishingly, that's where we are.
Cataclysmic
"This could be cataclysmic for the firms affected. It's no exaggeration to say there are 24 hours to save Scottish businesses."
Mr Golden added: "We all support the principle behind the DRS, but in its current form it's not fit for purpose and risks signalling the death knell for Scottish businesses, which face being burdened with unsustainable costs."
Circularity Scotland, which is responsible for running the scheme, recently announced £22million of support to remove upfront charges from some companies.
However, industry body UKHospitality Scotland has also backed an independent review.
Executive director Leon Thompson said: "The flawed model, complexity and burdens of the scheme will put unnecessary pressure on both businesses and consumers, who are all struggling with the cost-of-living crisis."
It was also reported yesterday that the DRS scheme could be dead in the water after the UK Government signalled that it would block the "inflationary" project.
Opt-out needed
Ms Slater has admitted that an opt-out from Britain's Internal Market Act is needed for the scheme to proceed.
A UK source said: "The present scheme is in deep trouble, and that is before the UK Government has been asked to relax laws protecting cross-border trade."
Alister Jack, the secretary of state for Scotland, told the Commons last week that the bar for an exemption "is very high indeed".
He said: "Aldi will sell 12 bottles of Scottish water for £1.59. Under this scheme, that will become £3.99. If that is not inflationary, if that is not adding to people's cost of living, I do not know what is."
Mr Jack has urged the Scottish Government to pause the system and work with the UK on a method that could operate nationwide.