Extinction Rebellion plots to 'take over Windsor Castle' grounds

The group quoted Charles' book Harmony, which was penned during his time as the Prince of Wales.

They wrote Charles “clearly understands the plight of the planet and the urgent need for society to change course”.

Extinction Rebellion acknowledges the 75-year-old monarch has been less vocal about climate change since succeeding Queen Elizabeth II to the throne.

Charles was invited to join protesters for “three days of beauty, community, action and democracy”.

The group added: “The occupation will unite everyday people fighting for climate justice, global justice, social justice, and justice for nature, to demand an upgrade to our democratic system.”

The “peaceful event” is intended to advance the group’s demand for the UK to create a citizen’s assembly on climate and ecological justice.

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Extinction Rebellion’s Catherine Bartlett said: “Windsor Castle has been chosen as an embodiment of a broken and unjust system where our message will resonate powerfully.

“The General Election has neither fixed our broken system nor addressed the urgent action needed to tackle the climate and nature emergency.

“Aristocrats, oligarchs and corporate interests have infected and distorted our politics and media for their own benefit and at our expense.

“Our politics is failing us from top to bottom. It’s time for a democratic upgrade.

“We demand better at all levels; from the head of state to local councils but our central demand is for a citizens’ assembly on climate and ecological justice, which is needed more urgently now than ever before.”

Charles was informed about Extinction Rebellion’s plan on June 13, with the group requesting the monarch does everything he can to facilitate the protest.

In a letter, the group said: “On the weekend of August 30 to September 1 we will bring thousands to your door in Windsor to protest at the failure of our Government to act on the science of climate change and ecological collapse.

“We refuse to bequeath a dying planet to future generations by failing to act now.

“We act in peace, with ferocious love of these lands in our hearts. We act on behalf of life.”