The team behind the latest plans to build a barrage across the Bristol Channel say that the project needs to get the green light within the next three years or risk being dumped.
Hafren Power, which is made up of a consortium of businesses, has put together plans for a £25-billion scheme which would see a 12-mile barrage built between Brean Sands in North Somerset and Penarth in South Wales.
The previous government had abandoned the plan after a major study but Hafren is confident it can pay for the project with private funding.
Earlier this year David Cameron, who is a keen advocate of green energy, appeared to give his backing to the ambitious project.
Plans for a barrage, which have been on the drawing board for more than three decades, would create enough clean energy to supply five per cent of the country’s energy needs.
Backers including former government minister Peter Hain say the project would create thousands of jobs in the South West but Bristol Port has spoken out against the barrage.
Hafren Power has been holding talks with government ministers and environmental groups who say a barrage would destroy the environment along the Severn Estuary.
And this week Professor Brian Morgan, who is a leading member of Hafren’s board, claimed that any further delays could end with the barrage “going into the long grass”.
A special Act of Parliament will have to be passed if the plans are to go ahead, and politicians in Westminster have signalled they would give their backing.
Professor Morgan said: “We do have a window of opportunity because we do have some support from the government, both in Wales and in Westminster.
“There is a lot of opportunity in terms of accessing sovereign wealth funds.
“But the UK government will be facing an election in 2015, so we would need to put a Bill through parliament and get it approved before the end of this government, to make headway because then it will go into the long grass.”
He added: “The issue that needs to be tackled and resolved is the consumer price subsidy that all renewable projects get – wind, biomass, solar and so on – at the beginning of their life.
“The Severn Barrage is no different. It needs a contract with an element of price subsidy for the first 25 years of its 100-plus year life, after which it is very cheap indeed.”
Neath MP former Welsh Secretary Peter Hain stepped down from Labour’s front-bench team to support Hafren Power’s plans.
He said: “The barrage is foremost a project to generate renewable clean green energy to help meet the serious threat of global warming and climate change.
“Unlike former projects Hafren Power’s concept is to generate on ebb and flow, emulating the current tidal regime. This makes it much more fish-friendly and means that there will be significantly less impact upon bird life and natural habitats.
“It will also act as an important flood protection barrier against rising sea level and storm surges caused by global warming.
“The design will be devised by specialists, resulting from intensive research into the complicated estuary tidal patterns.”
He added: “The former proposals were abandoned in part because they required significant public funds which proved too costly.
“Hafren Power require no treasury money at all: this is to be constructed entirely from private investment – over £25 billion, a huge amount, 80 per cent of which will be spent in the South West of England and South Wales creating some 50,000 jobs.
“Developing a green economy which generates jobs and produces clean, low-carbon energy should surely be a priority for all those serious about tackling climate change.
“The Severn Barrage is the most appropriate structure for the Severn as tidal lagoons and reefs would produce far less energy and are not necessarily smaller in scale or impact. Bristol Port will be unaffected as its existing shipping will pass through locks in the barrage at no charge.
“The Severn Barrage will generate fully five per cent of the UK electricity needs, a huge amount, the equivalent of three nuclear power stations or over 3,000 wind turbines.”
The Royal Society for the Protection of Birds recently met Hafren Power together with the Angling Trust and other green groups. The organisations say they want to see the plans before making a final decision.
There is also a question mark over whether the scheme will affect plans for a power station at Oldbury which were announced last week by Japanese firm Hitachi.