Thousands of “edible water bottles” will be handed out at the London Marathon for the first time this year, as organisers strive to cut down on plastic waste.

In the biggest experiment of its kind, around 30,000 liquid capsules made from seaweed are to be offered to parched runners along the gruelling 26.2-mile route on April 28.

The Ooho! 30ml sachets can be bitten to release the liquid inside - which is either Lucozade Sport or water - and are fit to be swallowed, minimising the risk of litter.

Pouches that are discarded can be easily swept up and are biodegradable, according to the creators.

They have been pioneered by a British-based start-up, Skipping Rocks Lab, which has already raised around £850,000 in a bid to slash plastic waste at sporting events.

It comes amid growing concern about the environmental impact of mass-participation races across the country, where streets are routinely turned into graveyards of discarded bottles.

Lise Honsinger, the CFO of Skipping Rocks, told The Daily Telegraph: “We’re very excited, in our fundraising pitch two years ago we said we were targeting events such as the London Marathon.”

“We’ve had great feedback, while they take a bit of getting used to, once people get them they find them almost easier to use than a cup.