Newcastle upon Tyne has been named as Britain's greenest city in a think tank's annual study.

Forum for the Future looked at the sustainability of the 20 biggest cities, measuring factors such as air quality, wildlife and quality of life.

Newcastle, which beat 2008 winner Bristol into second, performed well "on many measures of sustainability".

Brighton and Hove came third, with Leicester fourth and London fifth. Edinburgh was seventh and Cardiff 10th.

The study measured 13 indicators of environmental performance, quality of life and how well prepared the cities are for the future.

Peter Madden, chief executive of Forum for the Future, said: "Cities with an industrial heritage face genuine challenges, but Newcastle's success shows that it is possible to overcome the legacy of the past and perform well on many measures of sustainability.

"We hope it will inspire other cities to redouble their efforts."