Theresa May is set to double the plastic bag charge, she has confirmed.
A charge of 5p is already made for every new carrier bag in supermarkets but May is planning to double the cost to 10p, despite reports of opposition from Chancellor Philip Hammond.
Launching a consultation, the prime minister said she would also consider rolling out the 5p bag tax to small retailers, who currently do not have to charge for bags but which still supply three billion of them each year.
May said: “We have taken huge strides to improve the environment, and the charge on plastic bags in supermarkets and big retailers has demonstrated the difference we can achieve by making small changes to our everyday habits.
“I want to leave a greener, healthier environment for future generations, but with plastic in the sea still set to treble we know we need to do more to better protect our oceans and eliminate this harmful waste.”
Speaking from Kenya, May said the 5p charge had led to 13 billion plastic bags being taken out of circulation in the last two years and seen sales of the bags in supermarkets drop by 86%.
But Treasury sources are reported to have warned that increasing the charge to 10p could backfire, as it may look as though the government is trying to “profit” from the tax.
Hammond is reported to prefer tax incentives to charges, not only on plastic bags but also the planned “latte levy” on disposable coffee cups.
However, Environment Secretary Michael Gove welcomed the announcement.
“We are committed to being a global leader in tackling plastic pollution,” he said. “It blights our seas and land and chokes our wildlife.
“Thanks to the public’s support, our plastic bag charge has been hugely successful. It has taken 13 billion plastic bags out of circulation in the last two years alone.
“Today we are building on that success to ensure we leave our environment in a better state than we inherited it.”
Friends of the Earth plastic campaigner Emma Priestland urged the government to go further and ban single-use plastics altogether.
She said: “Marine animals are just as likely to choke on straws and coffee cups, yet these have so far escaped government action.
“Ministers must do more to force retailers to cut back on plastic – such as introducing a ‘latte levy’.
“But ultimately we need a clear plan to end the use of all but the most essential plastic.”