Each supermarket bag could cost 9p in future
Environment minister Michael Meacher has been following a scheme in the Republic of Ireland, where supermarkets charge for bags usually handed out free.
A spokesman for the Department of Environment, Food and Rural Affairs (Defra) said Mr Meacher was "interested" in a similar scheme for the UK.
However, he dismissed newspaper speculation that there was a commitment for it to be introduced within two years.
"There are concerns about the number of plastic bags that are routinely handed over by supermarkets.
"The number of plastic bags is a problem and the fact that so many go into landfill sites is a problem.
"Whether or not this would be a solution that would work in the UK - we would need more information."
10bn bags a year
It was reported on Sunday that the tax would be imposed on the supermarkets with a stipulation that they must pass it on to shoppers by charging for individual bags.
This would prevent any large chain from attempting to court popularity by paying the tax on customers' behalf, said the Sunday Telegraph.
Supermarkets welcomed the idea, with Asda saying it was "in everyone's interest", and Tesco saying it was important that environmental targets were reached.
About 10 billion plastic bags are given away at supermarket checkouts each year in Britain, costing the stores an estimated £1bn.
Plastic supermarket bags are a major cause of litter and take several years to decompose naturally.