An index listing the most adulterous boroughs in London has been topped by Kensington and Chelsea and Hammersmith and Fulham.

The Royal borough has the highest percentage in the capital of people cheating according to new data, and is followed closely by Hammersmith and Fulham.

The figures have been released by website which specialises in dating for married people, and is based on its own extensive data on the numbers of Briton’s cheating.

It says there are 8,520 cheating on their partners in K&C, meaning 5.67% of the borough’s couples are seeking excitement outside their marriage.

And next on the Illicit Index list is neighbouring H&F, with 5.57% (9,951 people) of couples apparently having affairs.

Also ranking in the top 10 are Brent (fifth with 5.17%) and Ealing (10th with 3.53%).

'Soaring house prices leading to affair boom'

The website says financial constraints may be a reason is has seen a 20% surge in registrations over the past five years.

Spokesman Christian Grant said: “London is enjoying a boom in extra-marital affairs because spiralling house prices have made divorce increasingly difficult for many couples in the capital.

"They are struggling along unhappily because they simply cannot afford to set up two homes.”

The site claims most men on its site are highly paid (average salery £54,000) and in professional jobs, fitting the K&C demographic which has some of the country’s most expensive properties.

Top 10

Borough Percentage People
Kensington & Chelsea 5.67 8520
Hammersmith & Fulham 5.57 9951
Islington 5.54 11145
Bromley 5.29 16807
Brent 5.17 16388
Tower Hamlets 5.12 13985
Camden 4.06 9316
Merton 3.84 7794
Wandsworth 3.8 11813
Ealing 3.53 12096

Selected others

Hillingdon 3.17 9097
Harrow 3.1 7538
Hounslow 2.5 8005
Westminster 2.35 5327