Half a million Britons admitted that they wash their bed sheets three times a year, according to the survey of 1,029 men and women aged 18 and over, done by Sheilas' Wheels home insurance. One in six people admitted that they had to wait at least a month before washing their bed sheets.

Mothers under 25s were found with the dirtiest bed sheets. Over 55s wash their dirty sheets on average three times a month.

"An unsavory, 42% of the British population, regularly enjoys a bite to eat in bed. America's Environment Health and Safety Online found a typical used mattress may have anywhere from 100,000 to 10million mites inside. Washing your bedding takes time and effort, but to reduce levels of unwanted organisms and mites you need to wash your bed linen at least once a fortnight, preferably once a week", said Dr. Lisa Ackerley, an environmental health practitioner.

Some of the dirtiest regions are London 24%, north east 22%, south west 21%, south east 19%.