Experts say prolonged delay in replacing chair signals that government does not take net zero policy seriously enough and is harming investment

Rishi Sunak has come under fierce attack from UK climate experts for his government’s failure over the past 18 months to appoint a new chair of the independent committee that advises ministers on emissions targets.

In a letter to the prime minister leaked to the Observer, the UK’s leading organisation working on the economic effects of global warming condemned the “excessive delay” in finding a replacement to previous chair Lord Deben.