Plans for a Severn Barrage are under scrutiny at Westminster today. Supporters say it'd create jobs and provide five percent of the UK's energy needs.
But enviromentalists warn it could be devastating for wildlife.
Owain Phillips reports.
MPs say developers "failed to address commercial and environmental concerns" in the barrage plan and the scheme's viability isn't proven.
Bristol Port attack barrage project, but unions champion the economic boost to South Wales.
The Prime Minister instructs ministers to explore the development of a hydroelectric barrage across the River Severn.