The UK Government is to re-examine proposals for a £30bn project to generate electricity from the tidal power of the Severn Estuary.
The proposals, by a private sector constortium, could potentially create 20,000 jobs during the construction. The barrage is expected to generate about 5% of the UK's energy needs.
Following a feasibility study from 2008 -2010, the Government turned down the plans citing reasons of cost overruns.
Earlier this year, Peter Hain quit his post as Shadow Welsh Secretary in order to focus on leading a campaign in Parliament to back the barrage plans.
– Department for Energy and Climate Change spokesman
“The Government is open to working with affordable, environmentally-responsible projects that represent good value for consumers.
“So far, we have only seen a very draft and high level outline business case from the consortium.
“Even if this proposal can meet our criteria it has a long way to go in development”.
Previously, Friends of the Cymru have warned that the environmental consequences of building the barrage could be severe.
In May, the group's director, Gareth Clubb, said the tidal barrage would "destroy" vast areas of habitat and "devastate" fish and bird life.
He says he agrees that using Wales' natural resources for renewable energy is important in tackling climate change, but believe that the barrage could be the "wrong solution."