Powys 'mega dairy': Public inquiry into Leighton refusal
5 March 2013 Last updated at 08:10 GMT
A public inquiry is due to begin into Powys council's decision to block planning permission for a "mega dairy".
The authority refused consent for the farm near Welshpool, which wants to expand from milking 300 cows to 1,000.
The National Trust and Countryside Council for Wales are expected to give evidence that the expansion would have a significant impact on the surrounding area.
Environment correspondent Iolo ap Dafydd reports for Radio Wales.