The Co-op is developing a fully biodegradable tea bag free from synthetic materials in a bid to find a solution to the plastic pollution caused by the nation’s favourite hot drink.

The supermarket chain’s own-brand 99 tea will be made without polypropylene – the material that allows tea bags to hold their shape – saving nine tonnes of plastic each year from being dumped in compost or landfill.

It is developing its new bag with tea supplier Typhoo and technology company Ahlstrom-Munksjö, which specialises in sustainable fibres.

They aim to develop a new method of heat sealing the bags to eliminate the plastic seal used currently.

The new bag will undergo testing in February and should hit the shelves later this year.

Jo Whitfield, chief executive of Co-op Food, said: “Many tea drinkers are blissfully unaware that the teabag from their daily cuppa is sealed using plastic.

“Even though it’s a relatively small amount, when you consider the six billion cups of tea that are brewed up every year in the UK, we are looking at around 150 tonnes of polypropylene – that’s an enormous amount of accumulated plastic waste that is either contaminating food waste compost collections or simply going to landfill.

“A cup of tea is part of our national psyche, so we felt it was imperative that we fix the problem as soon as possible.

“We’re absolutely committed to reducing plastic in our packaging and want to ensure that tea lovers can enjoy a guilt-free brew.”

The Co-op aims to ensure 80% of its packaging is recyclable by 2020.