Mr Cairns has received a letter from E-ON Climate and Renewables UK Ltd stating that they have abandoned plans to build 30 giant wind-turbines at Scarweather Sands.

David Farrier, director of the project, said that the firm, in conjunction with partners DONG energy, had decided not to proceed with the project.

He said that since the lease was first awarded in 2003 by the Crown Estates, both companies have been involved in larger offshore wind projects throughout the UK and Europe and now feel that the scheme is not commercially viable. They will be handing the lease back to the Crown Estates.

"This represents a victory for the people of Porthcawl who were largely opposed to the windfarm," said Mr Cairns. "There were always doubts about its viability and I am delighted for the hard core of opponents who never gave up the fight even after planning consent was granted."

There was considerable opposition to the scheme because of visual intrusion but also for environmental reasons as the site is the breeding ground of the harbour porpoise which is a protected species.

Mr Cairns said that there was a chance that another firm could take over the lease but that seemed unlikely if it was now considered that Scarweather was not viable.

"We must be vigilant in case someone tries to come forward with a larger scheme which would be even more intrusive and damaging," he added.