Yesterday, on World Environment Day, HS2's CEO lauded the controversial project as "Britain's biggest environment project" - and people were not happy.

Critics branded the comments "greenwashing of the worst kind", adding that the railway line - which will cut through the Chilterns - is an "environmental disaster".

HS2 proudly reeled off a list on social media of all the benefits it believes the project will provide, including tree planting, but not many people in the comments agreed.

Friends of the Earth criticised the organisation for "trying to hitch a ride on World Environment Day", adding: "You can't replace ancient woodland with saplings."

Dr Sean Perkins said: "Greenwash. Ancient woodland is irreplaceable and this project is destroying significant amounts of our precious remaining habitat."

Andrew Knapp added: "You don't 'create' wildlife habitats. Wildlife habitats take many years or even centuries to full establish themselves. Though they can easily be destroyed overnight by idiotic planning."

And RSPB England, the wildlife charity that runs a number of reserves in the country, said: "Really HS2? How can a scheme that, by its own figures, will lead to a three per cent net loss of replaceable habitats and 17 per cent loss for Phase 2a claim to be Britain's biggest environment project?

"Department for Transport, please respond to our request for the scheme to meet best practice for nature."

HS2 CEO Mark Thurston said yesterday: "Our ambition at HS2 is to design and build the most sustainable high-speed railway in the world, so that we can play our part in helping the UK to tackle climate change, improve air quality and reach net zero carbon emissions by 2050.

“But it is just as important for us at HS2 that we protect the natural environment and leave behind richer, more diverse and better-connected landscapes and wildlife habitats."