Activists from Greenpeace were arrested Thursday after scaling UK Prime Minister Rishi Sunak's constituency home in northern England and covering it with black fabric to protest his fossil fuel policy.

Sunak this week approved hundreds of new oil and gas licences in the North Sea off Britain's east coast, angering environmentalists.

"We desperately need our prime minister to be a climate leader, not a climate arsonist," said Greenpeace UK climate campaigner Philip Evans.

"Just as wildfires and floods wreck homes and lives around the world, Sunak is committing to a massive expansion of oil and gas drilling."

Greenpeace UK posted videos of four activists climbing onto the roof of Sunak's mansion in Richmond, north Yorkshire, and covering it with black sheets.

It later said that the activists, who spent around five hours on Sunak's roof, had been arrested.

Two more activists unfurled a banner reading "Rishi Sunak -- Oil Profits or Our Future?" on the front lawn.

The prime minister and his family are currently on holiday in California.

"He seems quite happy to hold a blowtorch to the planet if he can score a few political points by sowing division around climate in this country," said Evans.

"This is cynical beyond belief."

Separately, dozens of mothers joined forces outside parliament to demonstrate against the government's policy.

"We all know that climate science screams that we cannot have more fossil fuels... I am really furious on behalf of my kids," said protest organiser Lorna Powell, 37.

"Instead of being a climate leader and acting in the right way, he's decided that he is going to use it as a political game to try and stoke a culture war," she added.

Downing Street insists the policy is essential to ensure Britain's domestic energy security, and that it can still meet its 2050 net zero goals.