The outspoken former Bishop of Birmingham, the Rt Rev Hugh Montefiore, has died at the age of 85.
Hugh Montefiore was Bishop of Birmingham from 1978-87
The environmental campaigner was forced to resign from the board of Friends of the Earth (FoE) last October in a dispute over promoting nuclear power.
The bishop, who converted to Christianity from Judaism as a schoolboy, chaired the campaign group between 1992 and 1998.
He was taken ill suddenly on his birthday on Thursday.
The bishop was taken to hospital and died in the early hours of Friday, a spokesperson for the Diocese of Southwark, where he lived, said.
Last year FoE said Rt Rev Montefiore's support for nuclear energy to tackle global warming was not compatible with the charity's aims.
The bishop, who believed the uptake of renewable energy sources was taking too long, said he was "sad" to be resigning.
He was Bishop of Birmingham from 1978 to 1987 and an FoE trustee for two decades.