The debate intensified yesterday as the deadline passed for responses to the proposal to build 181 wind turbines on the island of Lewis.

Comhairle nan Eilean Siar (Western Isles Council) will almost certainly recommend approval but it will be up to ministers to take the final decision and they will not do so until after the Scottish parliamentary elections in May.

The protagonists are giving food for ministerial thought. Last week the Royal Society for the Protection of Birds (RSPB), which is opposed to the £400m development, challenged the developers' claims that the development would bring more than of 230 jobs.

Yesterday, developers Lewis Windpower, a partnership between Amec and British Energy, hit back. David Hodkinson, Lewis Windpower director, said: "It appears to us that RSPB's attempt to discredit the work we have commissioned in respect of the economic development potential of the wind farm is a sign of their desperation to shift the debate away from the bird interests that are at the heart of their charitable status and royal charter.

"We expect one of the reasons for this is their desire to conceal their inconsistent approach to the protection of red-throated divers.

"We estimate the risk posed by the wind farm, which RSPB says would have a catastrophic' impact on these birds, is a tiny fraction - less than 1% - of that posed by the offshore project in the Thames Estuary, which RSPB welcomed.

"We issue a challenge to RSPB to explain how they see this apparent economy with the facts fitting with their obligations as a charity."