CLIMATE change and fuel poverty campaigners are set to demonstrate in London on Satuday after the country endured searing high temperatures this week.

It comes as the High Court ruled that the government broke its own climate change laws by failing to properly assess its net zero policies.

Climate activists from across the country are planning dozens of “swarm” marches from various meeting points across London, converging at Parliament Square for a symbolic mass sit-down.

The demonstration, jointly organised by Just Stop Oil, Fuel Poverty Action and the Peace and Justice Project under the banner of We All Want to Just Stop Oil, will then gather in a park for a picnic and small discussion groups.

Protesters are demanding no new oil projects, the taxation of big polluters and billionaires, an end to families having to choose between heating and eating, more insulation for homes and cheap public transport.

Organisers said: “This day is not about fine speeches from the great and good – it’s about getting together with each other, connecting, and empowering each other to step up.”

Their call for action follows a report from the National Energy Action (NEA) predicting that if average bills reach £3,250 per year, it will place 8.2 million households in fuel poverty.

The “huge increase” in 12 months adds to a rise in October which saw average energy bills reach £1,271, leaving 4.5 million households in fuel poverty, the charity said.

NEA chief executive Adam Scorer said: “We are facing the bleakest of winters.

“Energy bills are already unaffordable for millions and millions more are set to suffer.”

Shadow climate change minister Kerry McCarthy told Tory ministers in the Commons yesterday to get their “act together” after the High Court ruled on Monday that the government’s net zero strategy breached the Climate Change Act.

Ms McCarthy said the High Court was clear that “adding up the emissions cuts in the strategy will leave a 5 per cent shortfall.”

The Labour frontbencher said that “ministers can’t even do basic maths.”

Ms McCarthy said: “We are here because the High Court have ruled that the government’s net-zero strategy is unlawful and is in breach of the Climate Change Act.”

Business Minister Greg Hands said the government is considering an appeal.

In a hugely embarrassing ruling, Mr Justice Holgate found the net-zero strategy “lacked any quantitative assessment of the contributions expected to be made by individual policies to reductions in [greenhouse gas] emissions.”

The court ordered that the existing strategy be fleshed out with details necessary for parliamentary – and public – scrutiny within the next eight months.

The legal challenge was jointly brought by the Good Law Project, environmental campaigner Joanna Wheatley, Client Earth and Friends of the Earth.

Ms Wheatley said: “What’s needed is bold practical action across every aspect of our lives, right now. The High Court decision throws a lifeline, a very last chance for government to do the right thing.“

Friends of the Earth lawyer Katie de Kauwe said: “[The ruling] shows that the Climate Change Act is a piece of legislation which has teeth, and can, if necessary, be enforced through our court system if the government does not comply with its legal duties.”

Client Earth senior lawyer Sam Hunter Jones said: “This decision is a breakthrough moment in the fight against climate delay and inaction.

“It forces the government to put in place climate plans that will actually address the crisis.”

The government was been ordered to pay the legal costs of the complainants.

For more information on where to join the march, visit weallwanttojuststopoil.com