WE need to talk about plastic. That will be the message from Lord Mayor Keith Orrell and Prof Callum Roberts, an advisor to the BBC's iconic 'Blue Planet' series, at the Mansion House on Tuesday.

The pair will be speaking out in support of the York restaurants, cafés, pubs and other businesses which have joined 'refill' schemes to let people refill empty bottles with tap water. The aim is to reduce the number of plastic bottles and cups thrown away.

"A billion plastic bottles filled with water are sold world-wide every day, with the majority discarded when empty," Cllr Orrell said. "Refill aims to stop this appalling waste with its associated environmental pollution by enabling people to refill their empty bottles rather than replace them."

Prof Roberts, an expert on marine pollution at the University of York who was an advisor on Blue Planet, said single use plastic was having a devastating impact on our seas and oceans.

"You only have to look at the beaches around our coast to see what a huge eyesore plastic is," he said. The plastic is far more than just an eyesore, however, he said: it's a serious threat to our health and our environment. It degrades over time into tiny particles which float in the water. These are then eaten by sea creatures, which are in turn eaten by the fish which we ourselves catch and eat.

We have to change our throwaway habits, Prof Roberts said. "It is senseless that a product we interact with for mere minutes will hang around in the environment for hundreds of years."

There are two 'refill' schemes operating in York which are backed by the city council. Refill York (supported by Yorkshire Water's Yorkshire on Tap) is part of a nationwide scheme which about 15,000 businesses have signed up to. Another scheme, I Am Reusable, has about 70 businesses in York. Both schemes use window stickers so people know they can get a refill.

Andrew Waller, the city council's executive member for the environment, said Tuesday's event was about raising awareness of the need to reduce single-use plastics. Council leader Ian Gillies added: “Every household and business can play their part. The smallest thing can make the biggest difference which is why we are so keen to have this important discussion in the Mansion House." Tickets for the event have sold out.