The body that acts as a watchdog for national parks is considering taking unprecedented legal action against a park authority over its decision to grant planning permission for a £60 million holiday village.

The Council for National Parks (CNP) has announced it will take the Pembrokeshire Coast National Park Authority to the High Court over its backing for the Bluestone project.

The CNP said the Bluestone project, a 500-acre, 340-lodge scheme in west Wales, would have "huge environmental impact".

The Pembrokeshire Coast National Park Authority went against the advice of its watchdog to grant planning permission for the private development.

In the first legal action against a park authority since it was created in 1936, the Council for National Parks is seeking a judicial review of the decision in the High Court. The council had warned the authority that the development could cause serious harm and set an unwelcome precedent.

The holiday village site is partly on the Pembrokeshire Coast National Park and so the park authority is required to give approval and gave its unanimous backing last month. Now the watchdog has called for the Welsh Assembly, which has so far backed the project to the tune of £16.5 million, to intervene.

The Bluestone project boss William McNamara had been expecting the legal move and said that all the correct procedures had been followed. There had been a long planning process to ensure it was not open to legal challenge.

McNamara told BBC Wales: "There are no public rights of way. Ecologically it is a very poor area. The reality is that this proposal has been democratically voted in. What they are challenging is the fact they don't like the decision."

The leisure and sports village would create 600 permanent jobs, said the developer who criticised the watchdog for its "predictable delaying tactic".

Ruth Chambers said, “we have been accused of delaying tactics because we have been considering a legal challenge of the Park Authority’ decision. That really misses the point, as a legal challenge of a planning authority’s decision is an established part of our land use planning and legal system. Legal challenge is now the only way to protect the National Park from the Bluestone development.”