There is a "strong case" for a sustainable Severn barrage to be built - but only if it is a public project which complies with environmental laws, a report has found.
The Sustainable Development Commission report revealed tidal power could supply at least 10 per cent of the UK's electricity if fully exploited and a 10-mile Severn barrage "could generate large quantities of low-carbon electricity for 120 years".
But the SDC said the project must be public sector-led and publicly-owned to ensure the public gets a fair share of the rewards of the £15bn scheme.
And it said there must be a long-term commitment to creating alternative habitats to compensate for around 11,000 hectares that would be lost.
The commission also warned the project must not detract from much wider government action on climate change, including simple measures such as energy efficiency.
The authors of the report, Turning the Tide: Tidal Power in the UK, said they were not persuaded by arguments for tidal lagoons as an alternative to the barrage.
But they recommended the government supported a trial project to establish if the technology worked.
The commissioners also urged the government to "stay the course" in supporting tidal stream technology, such as underwater turbines, in which they said the UK is a world leader.Reuse content