A “latte levy” on disposable coffee cups should be introduced in Wales to reduce waste, campaigners have said.
UK ministers rejected calls for a 25p charge per single-use cup in the Autumn Budget, proposing a plastic packaging tax instead.
Not-for-profit organisation City to Sea now wants the Welsh Government to take the lead, as it did with the 5p carrier bag charge.
Welsh ministers said they would continue to consider the matter.
They also said they would monitor voluntary action by businesses.
But City to Sea founder Natalie Fee said the issue was urgent and the Autumn Budget was a “very diluted tax” that would not change people’s behaviour.
“It’s been shown with the 5p bag charge – that when a charge is introduced at the point of sale – that it drastically reduces consumption,” she added.
“So not just [a focus] on recycling, because that’s still using tonnes of plastic, it’s still using tonnes of paper.
“Whereas when people are actually encouraged to bring a cup with them to a coffee shop and reuse, we are reducing resources and we’re reducing plastic use.”
About 2.5 billion disposable coffee cups, most of which are a combination of paper and plastic, are used in the UK each year.
Starbucks, Costa, Pret a Manger, Greggs and Caffe Nero all offer discounts on coffee bought in reusable cups in a bid to cut waste.
Neil Whittall, from the Paper Cup Alliance which represents leading UK paper cup manufacturers, called a “latte levy” unnecessary as its cups were 100% recyclable and consumers wanted more recycling.
“The industry has come together in force to improving recovering and recycling of paper cups. That’s a better way for the consumer to be treated and the industry is committed to increasing those rates,” he said.
He warned a tax could prompt huge job losses in the coffee market and said on-the-go coffee cups and plastic bags were difficult to compare.
The Welsh Government said it was “working closely with UK government on the forthcoming packaging tax consultation to ensure that the Welsh Government continues to be a part of the engagement, policy development and implementation processes for any taxation measure in this area”.
A spokesman said ministers could seek powers that included a tax on single-use cups, but wanted to assess the evidence in a UK government consultation first to ensure any approach “works for Wales”.
Sunday Politics Wales is on BBC One Wales at 11:00 GMT on 20 January.