The German system is estimated to have cost about £600m (726m euros) as an initial set-up in 2003, and about £700m (793m euros) annually for maintenance.

A Department for Food, Environment and Rural Affairs (Defra) spokesman told Reality Check: "It's important to recognise that not all deposit return schemes are the same. The specific model, scope and scale of any scheme can have a significant impact on costs and will be part of the consultation."

Has the UK ever had a deposit return scheme for bottles?

From the 1960s, a money-back deposit scheme was introduced in the UK for glass bottles - but this died out with the advent of cheap plastic bottles in the 1980s.