Pret A Manger offers 50p discount on hot drinks in reusable cups
The chain introduced a 25p discount for those opting not to use paper cups in August, and in December chief executive Clive Schlee said it would be doubling the amount from the first week of this year to encourage customers to reduce rather than rely on recycling.
He tweeted today: "I'm delighted you can now get 50p off a hot drink when you bring your reusable cup to @Pret. I hope this will make a difference."
Academics at Cardiff University have estimated that 2.5 billion disposable coffee cups are used in the UK every year, with about 25,000 tonnes of waste created.
It is estimated that just one in 400 of the cups is recycled as it is difficult to separate the cardboard from the plastic lining that makes them waterproof.
Mr Schlee has also said Pret will source a "well-designed" reusable cup to launch later this year and will explore adding china cups to more of its shops with seating.
He wrote in his December blog post: "Last week I tweeted that Pret was considering increasing its discount from 25p to 50p for any customer bringing a reusable cup. We are thinking of doing this to help change habits. It's well known that 'reduce' is better than 'recycle'.
"We debated whether charging people for using paper cups felt right. We decided that it goes against our instincts as we would prefer to be generous to our customers than to tax them. Let's see what impact the new discount has ..."
Chancellor Philip Hammond signalled that taxes or charges could be levied on single-use plastics to help the UK lead the way on tackling "the scourge" littering the environment in his November Budget statement.
It comes amid rising concern about the problem of plastic waste in the oceans, harming and killing wildlife and entering the food chain, highlighted most recently in the BBC's Blue Planet II documentary.
It follows the introduction of a 5p charge on single-use plastic carrier bags, which is credited with driving down how many are used by 85%, and calls to bring in charges on items ranging from plastic drinks bottles to disposable coffee cups.