TENS of thousands of people are expected to descend on Westminster this weekend to join Britain’s biggest ever protest against the combined climate emergency and political crisis.

The four-day action organised by Extinction Rebellion (XR), which will be joined by actors, authors, musicians, trade unionists and human rights activists, is demanding that the government takes immediate action to tackle the linked crises.

“People’s pickets” were formed outside 16 government buildings earlier today to kick off the campaign of protest, calling for urgent new policies to tackle the climate emergency affecting people and communities across the country.

Each picket had its own programme with speakers, who included writers Zadie Smith and Natasha Walter, Green MP Caroline Lucas and musical guests and street performers.

Ahead of the action, XR spokesman Rob Callender said: “While we suffer the cost-of-living crisis, oil company shareholders rake in record profits.

“The people know it’s not a crisis, it’s a scandal. So we’re setting up people’s pickets at these departments until they negotiate with us.

“And we’ll be back when the civil servants strike on the 28th. And we’ll be back when the nurses strike on the 30th.

“Because we’re all in this together. Tackling the climate crisis means creating a better, fairer, more caring society for everyone.”

Tomorrow, about 50,000 people are expected to pour into London to join a march for biodiversity in collaboration with Earth Day organisers, XR said.

The demonstrators will gather in Parliament Square at 12pm for a Unite to Survive rally, followed by a march and mass “die-in.”

Global Justice Now director Nick Dearden said: “The government and their tame media and business friends have had 30 years to tackle the crisis that is threatening all of our futures and they have done almost nothing except make it worse and more dangerous.

“We’ve had enough. We’re here uniting to survive.

“This is the start of something big — a show of unity by groups representing millions that will grow into an unstoppable movement this year to give the government no choice but to end the lethal madness of business as usual.”

Sunday’s events will target the Home Office over the government’s attacks on migrants and the continued use of fossil fuels.

Further details can be found on the XR website.