More than 100 authors, musicians, actors and artists have written to Boris Johnson urging him to extend the public’s right to roam over the English countryside.

The letter, signed by leading figures from Stephen Fry to Jarvis Cocker, Sir Mark Rylance to Ali Smith, calls on the prime minister to give people greater access to nature to improve the public’s physical and mental health.

“In the books we write, the songs we sing, the art that we make, we celebrate the essential connection that we feel with nature,” the letter states. “Our love for nature resonates with our millions of fans and followers, but in England, it is actively discouraged by the law. This is not only unfair; it is also untenable.”

The authors point out that in England the public has “freedom to roam” over only 8% of the country, while “only 3% of rivers in England and Wales are legally accessible to kayakers, paddle-boarders and wild swimmers”.

They are calling on Johnson to go further by extending right to roam to cover woodlands, rivers and green belt land.

“Lockdown has demonstrated how vital it is for us to have access to green outdoor space, both for our physical and our mental health,” the signatories write. “There is now a body of scientific evidence showing just how essential nature is for our wellbeing.”

The intervention comes on the 20th anniversary of the Countryside and Rights of Way (CRoW) Act, which created a partial right to roam in England and Wales. The letter was organised by the right to roam campaign, set up earlier this year by the authors Nick Hayes and Guy Shrubsole.

Shrubsole said: “Extending right to roam would be a bold and far-reaching act by this government, and its effects would resonate for generations to come. Now, more than ever, the time is ripe to give people the freedom to reconnect with nature, for the sake of public health.”