British cities have ranked poorly against European counterparts for quality of life in a survey of world cities, which claimed Birmingham was a "better" place to live than Rome.

Toxic air and traffic saw London – the UK's best performing city – this year drop one place to 40th in the annual Mercer 2017 index, with the capital joining New York (44th), Tokyo (47th) and Paris (38th) as global centres which failed to even reach the top 30.

European cities made up eight of the top 10 spots, which included Vienna – Austria's capital on the Danube river – as the number one-ranked city in the world for the eighth year running.

Beaten by many of its European neighbours, Britain also lagged behind Canada, New Zealand and Australia.

The coastal cities of Auckland, New Zealand and Vancouver, Canada were ranked third and fifth respectively, while Sydney, Australia was given joint 10th place.

The highest ranked city in the United States was San Francisco, California, at 29th, while Asia's best performing city was Singapore, at 25th.

Baghdad is again considered the worst place to live, with the Iraqi city still suffering from conflict, political unrest and poor infrastructure.

The Mercer Quality of Living survey ranks cities based on social and economic conditions, political stability, health care, education, crime, housing, transport and the environment. The consultancy firm uses the data to help multinational companies compensate employees fairly when placing them abroad.

It saw cities like Birmingham and Glasgow ranked higher than global tourist destinations like Rome, Los Angeles and Dubai.

London was last year ranked at 39 but dropped one place in the latest survey due its toxic air and traffic.

Edinburgh was the only other UK city to make this year's top 50, at 45th place, while Birmingham and Glasgow were joint 53rd. Aberdeen featured at number 58.

Kate Fitzpatrick, Mercer's global mobility practice leader for the UK & Ireland, said: "The capital's only downfall in regard to infrastructure is heavy traffic congestion, which also contributes to the city's low score for air quality and pollution."

Mercer 2017 UK cities ranked

40. London

45. Edinburgh

53. Birmingham and Glasgow

58. Aberdeen

Despite the low score compared to European neighbours, Fitzpatrick said British cities "remain attractive locations for multinational companies and their employees as they continue to rank highly for quality of living."

The global consultancy firm warned any negative fallout from Brexit could see the city drop even further down the rankings, however.

For a full list of Mercer's rankings, visit their website.

Mercer Quality of Living rankings 2017 – Top 10

1. Vienna, Austria

2. Zurich, Switzerland

3. Auckland, New Zealand

4. Munich, Germany

5. Vancouver, Canada

6. Dusseldorf, Germany

7. Frankfurt, Germany

8. Geneva, Switzerland

9. Copenhagen, Denmark

10=. Basel, Switzerland

10=. Sydney, Australia

Mercer Quality of Living rankings 2017 – Bottom 10

222. Conakry, Guinea

223. Kinshasa, Democratic Rep. of the Congo

224. Brazzaville, Congo

225. Damascus, Syria

226. N'djamena, Chad

227. Khartoum, Sudan

228. Port au Prince, Haiti

229. Sana'a, Republic of Yeman

230. Bangui, Central African Republic

231. Baghdad, Iraq