Coffee drinking is in danger after a new study found that 60 per cent of plants are now at risk of extinction, including the variety which produces most of the world’s beans.

Researchers at the Royal Botanic Gardens at Kew, have found that 75 of the world's 124 wild coffee species are under threat from the loss of forests, climate change and the worsening problem of fungal disease and pests.

They include wild Arabica, a species from Ethiopia that has been cultivated to provide 60 per cent of the multibillion-pound global trade in coffee.

Coffee farmers, who grow either Arabica or Robusta coffee, have already begun to report their crops being affected by changing weather patterns, rising temperatures and new pests and diseases.

Dr Davis, lead author of the study said: "What we're saying is 60 per cent is just really high, that's a real wake-up call. For a major global commodity, that starts ringing alarm bells.

"It's a tragedy losing any wild species, whether it's a bird or plant or animal, that's bad enough.

"But when you've got a crop that supports the livelihoods of 100 million people just in production in coffee farming, then you look at value of high street coffee chains and supermarket coffee, it's enormous."