Chris Packham has branded Cambridge University’s move to cover a row of trees with nets to stop birds from nesting as “absolutely outrageous”, with activists from Extinction Rebellion responding by tearing some of the netting down.

The conservationist’s social media post was prompted by photographs of the trees, with their branches completely encased in netting, on the university’s West Campus.

He wrote: “Seriously? I thought we’d been through this last year! This is absolutely outrageous!”

The Cambridge branch of Extinction Rebellion described the netting as “appalling” and demanded that it be removed.

It later posted photos of activists tearing down some of the netting under cover of darkness, adding: “We’ve freed some of the Cambridge Uni trees from their nets.”

The RSPB has previously said it is concerned by the use of netting on trees, hedges and bushes to prevent birds from nesting.

It is campaigning for laws to be introduced which would commit governments to ensure the recovery of nature, meaning such practices would come under greater scrutiny.

It is an offence to disturb nesting birds once they have arrived, but the practice of installing netting to keep them away is legal.

A Cambridge University spokesman said: “Trees near the Whittle Laboratory have had nets put over them to discourage birds from nesting in them, so they will not be disturbed by work to expand the lab.

“The netting will be checked for wildlife three times a day.”