UK to spend £5.8bn on tackling climate change in poor countries

David Cameron says cash spread over five years will come out of foreign aid budget as he meets Ban Ki-moon and Franiois Hollande at UN

Almost 6bn of the UK's foreign aid budget will be spent on tackling climate change in poor countries over the next five years, David Cameron has said, as Britain steps up its contributions by 50% to help meet international targets.

The prime minister will unveil the UK's offer at the United Nations general assembly, before crucial international climate change talks in Paris in December where nations are expected to collectively pledge $100bn (66bn) a year by 2020.