Plans to charge 5p for carrier bags to cut waste, litter and carbon emissions must be kept simple for the scheme to work, the Environmental Audit Committee has warned.
Ministers have been criticised for making the charge unnecessarily complicated by excluding small retailers and paper and biodegradable bag.
MP for Richmond Park Zac Goldsmith, who sits on the committee, has long campaigned for a charge on plastic bags.
Mr Goldsmith said: “Bags litter our streets and cause great harm to wildlife; they are the most obvious symbol of our throwaway culture.
“However the proposed policy is far more complicated than it needs to be, and could even end up harming the recycling industry.”