It is considered one of the most majestic waterfalls in north Wales, a mist-shrouded torrent that has inspired storytellers and artists for centuries.

But a fierce row has broken out over a scheme to harness the force of Rhaeadr y Cwm to generate electricity, with one of Wales’s foremost naturalists, Iolo Williams, the latest to step into a growing row over the project.

Williams, also a popular broadcaster, has added his voice to 1,000 protesters who have expressed fears that if the scheme goes ahead it will damage one of the most wonderful sights in Eryri (Snowdonia) and harm an important habitat for precious ferns and mosses.