M&S won't stop using ­polylactic acid (PLA) in its packaging, despite Innocent axing it because it can't be recycled by most councils.

Innocent will switch to PET bottles by January after it emerged PLA material could not be home composted, as claimed on bottles, or recycled alongside PET plastic bottles because it would contaminate them.

But M&S, which was last week criticised by the Local Government Association for the amount of its packaging that was not recyclable, said it would stick with corn-based PLA for produce and desserts. "PLA can be industrially composted and recycled, but most councils don't have facilities," it said.