If new EU water standards laws come into effect, holidaymakers would be urged not to swim at one in 10 English and Welsh beaches.
According to the Express, from 2015 all 500 beaches must meet the EU's revised Bathing Water Directive, which aim to reduce the exposure of swimmers to sewage and other pollutants in the sea and on beaches.
But the Environment Agency warns that currently about 10 per cent could fail.
This would lead to signs being put up to advise the public against bathing in order to prevent their exposure to pollution. And if a beach fails five years on the trot, 'permanent advice against bathing must be introduced' with the site removed from the list of designated bathing waters.
Details emerged as Keep Britain Tidy announced that 146 English beaches have won top awards including 70 Blue Flags which show that the area has high water quality and excellent facilities.
Torbay in Devon leads the way with six Blue Flags, followed by Cornwall and Southend with five each.
The Cleaner Seas Forum is this summer testing a warning system that will see beach managers putting up warning posters if a sewage pipe overflows.
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