The first minister Humza Yousaf has said that he is struggling to see how Scotland's deposit return scheme can go ahead without the UK government's support.
Yousaf has written to Prime Minister Rishi Sunak asking him to agree to include glass bottles in the scheme. He has set today (5) as a deadline for a response and agreed that this was "effectively" an ultimatum.
In his letter to the prime minister, Yousaf accused the UK government of placing the deposit return scheme (DRS) in "grave danger".
He said the demands would have a "significant impact" on business.
Citing concerns from one of Scotland's biggest brewers, Yousaf has urged a rethink from the UK government.
"The removal of glass fundamentally threatens the viability of Scotland's DRS with reduced revenue for the scheme administrator," he wrote. "Removing glass will also have a significant impact on business.
"For example, C&C Group - owners of the iconic Tennent's brand - has been explicit that the decision by the UK government to remove glass threatens investment and jobs. Other Scottish businesses have raised similar concerns privately with us."
Yousaf later told BBC Scotland Tennent's had said that, apart from threatening jobs and investment, excluding glass would also put the company at a competitive disadvantage.
"I'm not prepared to do that," he said. "The Scottish government will not be prepared to do that and now that we've heard from these companies I'm saying to the prime minister it's very simple - you agree to include glass in the scheme or I'm afraid I struggle to see how the scheme can go ahead because I will not put Scottish businesses at that disadvantage."
Yousaf said he hoped the UK government would listen and agree to provide the Scottish government with the necessary exemption from the Internal Market Act.
Yousaf also pointed out that the UK government had intended to include glass in the English DRS from 2019 right up until March 2022 - two years after regulations were passed by the Scottish Parliament.
"We planned our scheme on this basis," he said.
The first minister added that as late as January 2023, the UK government confirmed that it was for devolved governments to decide the scope of their DRS.
"The Welsh government's stated intention has been to include glass in their DRS, meaning that it is the English scheme which is out of step with the design of other UK schemes," Mr Yousaf said.
It is looking increasingly likely that the deposit return scheme will be scrapped.
The Scottish government wants the scheme to cover glass bottles, plastic bottles and drinks cans.
But the UK government has an effective veto - it needs to provide the Scottish government with an appropriate exemption from the Internal Market Act which is designed to ensure there are no barriers to trade within Britain.
