A 5p levy was introduced in Wales in October 2011 and in Northern Ireland in April this year, while Scotland is widely expected to do the same in October 2014. So far, though, there's been no move to do the same in England, for fear of antagonising cash-strapped voters.
Now, though, according to the Daily Telegraph, Cameron has confirmed that he's considering the issue. He's reported to have told schoolchildren and Break the Bag Habit campaigners in Downing Street: "It has been very successful in Wales and we are looking again at the options here. You have come at the right time as we are just discussing that."
Conservative MP Zac Goldsmith, who attended the event, said he was pleased by the Prime Minister's comments.
"The PM has spoken in the past about the need to take action, and it was reassuring to hear not only that he was discussing the issue today in Number 10, but that he has noted the successful bag charge in Wales," he said in a statement. "I know many people are looking forward to the next step here in England."
In England, by contrast, figures from the Waste and Resources Action Programme's (WRAP) indicate that plastic bag use has risen from 8 billion in 2011 to 8.1 billion last year.
But waste disposal companies have lobbied against a levy, claiming that most consumers reuse their plastic bags anyway.
"Carrier bags already include recycled content and many retailers already have provision for used bags to be returned for recycling," says Barry Turner, chief executive of the Packaging and Film Association (Pafa).
"If we were to take a similar approach to all the resources we use on a daily basis with charges and taxes imposed by central government on all the resources we use the economy would soon come grinding to a halt as consumers reeled in response to the extra cost burdens they had to bear."