Legislators in Wales have intervened in the planning application for a controversial 1,000-cow ‘super dairy’ in Powys.

Local councillors recently gave the development the green light but the final decision on whether the dairy can be built will now rest with Welsh ministers, not local planners.

In a letter to Powys County Council, Welsh environment minister John Griffiths said the planning application appeared to “conflict” with national policies on pollution control and on conserving the historic environment.

“Consequently, the minister hereby directs that the planning application… shall be determined by the Welsh minsters,” his letter said.

Animal welfare groups welcomed the move. Compassion in World Farming chief executive Philip Lymbery said dairying in the UK was under threat from “mega dairies”, and the Welsh government’s decision to call in the application was important “not just for those in Powys who object to the application but for the UK dairy industry as a whole”.

Local campaigner Holly Dyers said: “The final decision is still a long way off, but this is great news and a step in the right direction.”

The NFU said it could not comment on individual cases, but chief dairy adviser Rob Newbery said it was important to have a positive climate for investment in the industry.

“The NFU certainly supports modern, progressive dairy units,” he said. “Investment has been lacking in the industry for the past 10 years, so to see a farmer willing to invest is encouraging.”

Powys County Council conditionally approved the application in November.