THE designers of a "tidal reef" capable of harnessing the power of the Severn Estuary last night warned the plan could be "killed off" by bureaucracy hampering access to vital funding.

The reef is seen as a key rival to a controversial barrage from the Westcountry coast to Wales which would cause less damage to the environment.

It is claimed officials at the Regional Development Agency are planning to tie-up £500,000 in innovation money in time-consuming seminars and workshops instead of ensuring it reaches the researchers and engineers working on new green energy plans.

The fund was launched by Energy Secretary Ed Miliband last week in the latest stage of the Government's study into how up to five per cent of Britain's power supply could come from the waters off the Somerset coast.

While five more-advanced schemes – including a £22 billion, 10-mile concrete barrage from Cardiff to Weston-super-Mare – were shortlisted for meeting Government criteria already, the extra money was put forward to further develop less detailed ideas.

The reef concept is backed by environmental campaigners including the RSPB, WWF-UK, Friends of the Earth, the National Trust, the Wildlife Trusts and the Wildfowl and Wetlands Trust. They claim it would "minimise harm to the internationally important wildlife" in the estuary.

However, Evans Engineering, the firm behind the reef plan, has warned that unless the £500,000 is made readily available to start work on developing its plans, they will have to quit the race. Rupert Armstrong Evans claims officials at the South West RDA have told him it could take six months – half of the total project time – to make the funds available.

Mr Evans insists it would be "totally impossible" to deliver his project design in only six months, with less than a tenth of the funding of already spent on the Cardiff-Weston barrage.

He said Mr Miliband had been "very positive" about the alternative ideas last week, insisting the door is still open for another 12 months.

"To be told by the RDA in a yawning fashion that it could take six months to get their act together, hold a seminar and so on … basically it kills the prospect of making that deadline. I'm not in a position to write a cheque to carry on."

He insisted he would be "delighted" to press ahead with working on his plans, if the funding came forward more quickly. "If it is going through a long, bureaucratic process, I'm out. It's down to the politicians if they want it to happen or not."

The reef idea is favoured by the environmental lobby because it could cause less damage to the heavily protected wildlife habitats and migratory fish. However, the RDA insisted it should be possible for the reef scheme to attract private investment to develop designs alongside relying on the new fund.

Claire Gibson, director of sustainable resources at the South West RDA, said: "We would expect if these concepts are capable of being scaled up to the billion pound projects envisaged for the Severn Estuary, that they ought to be able to attract external finance to match this public sector investment."