Wildlife expert Chris Packham and more than 100 children will be delivering a petition to Buckingham Palace calling on the royal family to re-wild their estates.
Accompanied by parents, the campaigners will carry the Wild Card campaign petition – signed by 100,000 people – from Green Park tube station in central London to the palace at 10am on Saturday.
They will be led by a jazz band, and participants include the choir SOS From The Kids, who featured on Britain’s Got Talent in 2019 and will be performing a song.
Broadcaster Mr Packham is due to make a speech outside the palace, while a four-metre-tall sculpture of a white stork will carry a huge envelope symbolising the petition in its beak.
The Wild Card campaign is urging the royal family, who it says own 1.4% of the land in the UK, to conserve nature on their estates before they appear as ambassadors at the Cop26 climate summit in November.
Building on an open letter to the Queen sent in June by more than 100 scientists and celebrities including Hugh Fearnley-Whittingstall, Kate Humble and Anita Rani, the petition highlights issues with royal land.
The campaign states that while the average tree coverage is 37% in the European Union, the Duchy of Cornwall estate owned by the Prince of Wales has only 6% tree coverage.
Ecologists believe the royal estates would naturally feature beavers, wolves, bison, wild boar, pine martens and white storks, which could be introduced if re-wilded, campaigners have said.
The Wild Card campaign more widely demands that 50% of the UK be fully re-wilded, calling on the royal family as the UK’s biggest landowner to act first.
Royal-owned territories include the Crown Estate and the Duchies of Lancaster and Cornwall.