A leading trade body fears Scotland's deposit-return scheme will not be ready to launch in August.
The flagship initiative is designed to boost recycling via a 20p deposit on single-use drinks bottles and cans.
But the Scottish Retail Consortium (SRC) said its members, who must sign up by March 1, had yet to see an operational blueprint.
The Scottish Government said it was working with the industry to deliver the scheme.
The chief executive of Circularity Scotland, the newly-created company that will administer the initiative, told the BBC it would be ready for its launch date of August 16.
But Ewan MacDonald-Russell, deputy head of the SRC, urged ministers to provide clarity for his members by the end of this month.
Disruption fear
Otherwise, he warned, consumers faced disruption, higher prices and reduced choice.
Mr MacDonald-Russell said: "Despite this enormous investment, we are alarmed at the failure of government and the bodies it has approved to provide the key information needed for retailers to build a workable return system.
"We are already beyond reasonable deadlines for this scheme to land well in August."
Following a meeting with Circular Economy Minister Lorna Slater, Mr MacDonald-Russell said the scheme was in the "last-chance saloon".
He added: "Unless the Scottish Government and its partners can deliver a complete operational blueprint by the end of February, covering the key information retailers need to deliver the necessary infrastructure for DRS to succeed, we do not believe the scheme can launch successfully in mid-August."
He cautioned the potential fallout would see consumers face "a bewildering patchwork of approaches" that would make the recycling process "cumbersome".
Scheme charge
Under the scheme every producer based in Scotland will have to add a 20p to every product that they make before it is sold anywhere in the country. It will then be charged to the retailer who will, in turn, bill the consumer.
In order to recoup this money, people need to take the empty bottles or cans to a reverse-vending machine in a supermarket or designated return point.
Dougal Sharp, founder of brewer Innis & Gunn, told the BBC that there would be an additional 10p to 20p in admin costs per product associated with the scheme.
Put together that could mean consumers face paying an additional £1.60 for a four-pack of the company's craft beer and £4 for a 10-pack.
Mr Sharp said a "huge amount of infrastructure" was required ahead of the launch, from recycling centres to vehicles.
He added: "We are worried that the complexity of the scheme and the significant costs, both to producers and the end users, may jeopardise its success."