The government estimates that a mandatory 5p levy on plastic bags from retail outlets, due to come into force in October 2015, will raise £70m a year for good causes.
Dan Rogerson, the Liberal Democrat environment minister, told the Environmental Audit Committee last month that he expected the charge to raise a total of £95m a year – £70m of which "would go straight to good causes", according to the transcript of the meeting, published last week.
Of the remainder, £19m would go on VAT and £6m on retailers’ administration costs.
Retailers will be required to report back on where money raised by the scheme has gone, but there will be no legal obligation on retailers to give the proceeds to charity through the scheme.
Rogerson said that a combination of the government’s clear explanation of its expectations and "reputational issues" for shops should make it unnecessary to introduce primary legislation to ensure that the funds raised go to good causes.
Small businesses will not be obliged to take part in the scheme because of the administrative burden it could create.
Rogerson told the committee that if small retailers wanted to "make a donation to a local charity or something, that would be a wonderful thing to do".
The scheme was announced by Nick Clegg, the Deputy Prime Minister, at the Liberal Democrat party conference in September.
"We will discuss with retailers how the money raised should be spent, but I call on them to follow the lead of industry in Wales and donate the proceeds to charity," he said at the time.
The move will bring England in line with the rest of the UK. Retailers already charge shoppers for bags in Wales and Northern Ireland, where supermarkets have experienced an 80 per cent reduction in plastic bag use since the levy’s introduction. It will be introduced in Scotland in October.