A union has uncovered what it describes as "alarmingly high and dangerous" levels of dirt on Britain's streets and pavements.
More than one in 10 streets around the country suffer from "unacceptable levels" of dirt and refuse strewn about the surfaces, the GMB union has warned.
In the worst affected areas the level of filth rises so high that a fifth of the streets and pavements assessed by researchers were found to have unacceptable quantities of litter and other waste, while half were found to be dirty.
The study also concluded that the dirtiest and the cleanest streets in England are both found in London. Merton in south-west London was named as having the most dirty streets, while those in Kensington and Chelsea were the cleanest.
Officials from the union found that the level of cleanliness of the streets was largely in proportion to the amount of money councils were prepared to spend on keeping them clear of litter and other debris.
After Merton, Hounslow and North Hertfordshire were found to be the worst, with 44 per cent of land and highways assessed as dirty, while around 15 per cent of the streets in Hounslow and 6 per cent of those in North Hertfordshire had unacceptable of levels of litter.
Paul Kenny, the GMB's general secretary, said: "There is an alarmingly high and dangerous level of dirty streets and pavements in far too many places.
"On average the 12 per cent of streets that are officially classified as unacceptable is bad enough, but there are 129 councils in England that have a higher proportion than that, which is totally unacceptable.
"Local communities deserve clean and healthy environments. The GMB knows that clean streets are perfectly feasible everywhere; it's just a matter of ensuring there are enough properly trained and equipped street cleaners employed to do the job.
"Councillors should be clear that for street cleaning, as for other public services, you get what you pay for. The next thing that failed politicians may come out with is that people, as well as paying their council tax, should clean the streets themselves."
Over the 345 councils in England that were studied, 12 per cent of land and highways assessed had litter or other deposits that fell below an acceptable level.