The UKs largest environmental pollution claim is being heard at the High Court in London.
More than four and a half thousand people have accused regulator Welsh Water and chicken producer Avara Foods Limited of damaging the quality of three rivers on the border between England and Wales.
They claim the damage has been caused by a number of factors, including chicken manure being washed into the water and sewage discharges.
Ahead of the first procedural hearing in the case, the two companies call the claims "misguided".
The charity River Action is bringing the legal challenge - James Wallace is their chief executive…
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