If the scheme goes ahead, a lagoon would be built between Cardiff and Newport in the Severn estuary which separates England from Wales

A British firm on Monday launched plans to build a giant lagoon off the southern Welsh coast that would harness the tide to provide electricity for the whole of Wales.

If the scheme goes ahead, a would be built between Cardiff and Newport in the Severn estuary which separates England from Wales, featuring 90 turbines in a 14-mile (22-kilometre) breakwater.

The scheme, being planned by Tidal Lagoon Power, would have a capacity of between 1,800 and 2,800 megawatts, enough to provide electricity for every home in Wales.

"We have the best tidal resource in Europe and the second best worldwide. We now have a sustainable way to make the most of this natural advantage," said the firm's , Mark Shorrock.

"There is still a long way to go and many environmental surveys to undertake but we will work in partnership with all nature conservation bodies so as to understand, avoid, minimise and mitigate any environmental impacts."

A planning application for the scheme, which would likely cost several billion pounds, is due to be submitted in 2017.