The leaders of the UK's largest coalition dedicated to stopping climate change warned the Prime Minister on Tuesday not to go ahead with plans for a new coal plant at Kingsnorth.

The Stop Climate Chaos Coalition said that a green light for the plant "would lock Britain into decades of spiralling emissions and severely undermine the government's ability to meet its climate targets".

At the invitation of the local community, coalition representatives planted flags in the ground at Kingsnorth to show Gordon Brown the opposition he faces in giving the go ahead to a fleet of new unabated coal plants. Instead, the coalition is calling on the Prime Minister to invest in renewables and makes massive improvements to energy efficiency.

Ashok Sinha, Director of the Stop Climate Chaos Coalition said: "Gordon Brown's decision on new coal-fired power plants could be a defining moment in the fight against climate change.

"If he jumps the right way and unlocks Britain's renewable potential, we could show the rest of the world that low carbon technologies are the answer to the inseparable challenges of climate change, poverty and energy security.

"The reality is that a thriving renewables industry would help us avoid disastrous climate change, create thousands of jobs and keep the lights on."

The demonstration came on the same day as the publication of a report from a parliamentary committee warning that Government plans to develop new coal-fired power plants are "failing to take adequate account of the environmental impact of coal".

The report states that "replacing old coal-fired power stations with new ones, rather than using alternative energy sources, locks Britain into a high level of emissions for many years to come"

In a letter to Brown, the coalition says that Kingsnorth is one of the most important climate change decisions of his premiership and states that building new coal plants in the UK would send the wrong signal to countries like China and India, and could thwart a new global deal on climate change.

Paul Brannen, Christian Aid's Head of Campaigns, said: "Christian Aid works with vulnerable communities in poor countries who are already bearing the brunt of the impact of climate change.

"Global cuts in carbon emissions are urgently needed to prevent the situation worsening.

"Building a new generation of high-emitting coal-fired power plants without the technology to capture and store CO2 from the outset will take us further down the path to climate catastrophe."

The organisations argue that by transforming Britain into a low-carbon economy, the Prime Minister would prove the case internationally that renewables and energy efficiency can protect the climate and keep the lights on.

Tearfund's Advocacy Director Paul Cook said "A new coal-plant completely flies in the face of the Government's commitment to tackle carbon emissions. People in the poorest countries are already being affected by a changing climate.

"An 80% reduction in emissions by 2050 is vital in keeping global temperature rise below two degrees. New power stations would make this almost impossible."