A cashback scheme to recycle all plastic bottles could prevent a third of marine plastic waste.

That’s according to sustainable think-tank Green Alliance, which has outlined five solutions to UK Environment Secretary Michael Gove’s call for increased action on slashing ocean pollution – it says implementing them could prevent nearly two-thirds of the waste from ever reaching the sea.

The deposit return scheme would involve customers being rewarded for bringing back their old bottles.

A scheme like this in Germany is said to have resulted in nearly 100% of plastic bottles being returned for recycling compared to only 57% in the UK.

The group said the existing 5p carrier bag charge has tackled around 1% of the plastic problem and suggested committing to a microbead ban could tackle a further 1% of the issue if extended to all products.

The group recommends enforcing Operation Clean Sweep, a currently voluntary programme to prevent nurdles, the small pellets used to manufacture nearly all plastic products, from spilling into the environment.

It says making the scheme mandatory would prevent a further 9% of plastic pollution.

Another 11% could potentially be reduced by using coastguard patrol presence and electronic monitoring to enforce existing maritime waste bans.

Green Alliance says upgrading wastewater treatment plants with sand filters could capture a further 9% by capturing the minute plastic fibres washed into waste water when synthetic clothes are washed.