Britain faces growing calls at this week’s Commonwealth summit to pay billions of pounds in reparations to poorer countries for causing climate change as well as slavery.

The leaders of some of the nations at most risk from the effects of climate change plan to use the Commonwealth Heads of Government Meeting (CHOGM) in Samoa to lobby for reparative justice from the UK and other wealthy countries that are among the biggest polluters.

Philip Davis, the prime minister of the Bahamas, told the Observer that his country needed help from the UK and others to pay for damage caused by extreme weather events and to help save it from the worst effects of rising sea levels.