Bishops and other Christian leaders are taking part in The Big One climate protest march outside parliament on Friday.

The Big One is one of the biggest climate protests to date, with around 100,000 people expected to gather outside Parliament across the next four days to demand an end to the use of fossil fuels.

The former Archbishop of York and current chair of Christian Aid, John Sentamu, called UK government policy on the climate "an offence against humanity".

"Climate change is the most insidious and brutally indiscriminate force of our time. The people suffering the most have done the least to cause it," he said.

"That is why continuing to search for new sources of fossil fuels, despite explicit warnings against this from the International Energy Agency, is such an offence against humanity.

"If we want to limit climate suffering we have to leave fossil fuels in the ground. The Church has a proud history of standing up against injustice and once again we need to see Christians calling on the Government to take decisive action."

The Christian leaders will attend a No Faith In Fossil Fuels service at St John's Church, Waterloo, before marching past Shell HQ to join the Big One protest outside Parliament.

Andy Atkins, CEO of A Rocha UK, said, "It's now far beyond any reasonable doubt that the primary driver of climate change is burning fossil fuels.

"It is shocking that our government is encouraging new fossil fuel exploration in UK territory, despite the UN's science-backed call to end all new fossil fuel development to ensure a liveable planet for people and nature.

"This is beyond irresponsible; it is profoundly wrong and unjust to people alive now and to future generations.

"As a UK Christian nature conservation charity, whose supporters are UK citizens, we feel morally impelled to tell our government 'not in our name', and to pray for a change of hearts and minds."