Stratherrick & Foyers Community Trust, on the southern shore of Loch Ness, is angry at North British Wind Energy Ltd (NBW) for offering to pay less than half the industry benchmark in "community benefit" compensation for a 23-turbine wind farm on the Corriegarth Estate.
Corriegarth is the family estate of former Barings Bank stockbroker Andrew Fraser, who was last week revealed as one of the largest donors to Better Together, after giving £200,000. Fraser first entered into an "option agreement and licence" with NBW in 2008.
NBW is chaired by another Better Together donor, Christopher Wilkins, a former soldier with links to MI6, who recently gave £10,000.
Both Fraser and Wilkins are also significant shareholders in NBW.
NBW is offering to pay the Community Trust £2000 per megawatt (MW) to compensate them for the 50MW wind farm, whose turbines will be 120m high. Two neighbouring SSE wind farms will pay the Trust £5000 per MW.
Highland Council and Scottish Renewables, the body for the wind energy industry, also regard £5000 per MW as the industry benchmark.
If NBW were to pay £5000 per MW for Corriegarth, it would mean an extra £150,000 a year for investment in the local community, which needs more affordable and sheltered housing. Over the estimated 25-year life of Corriegarth, the extra would add up to £3.75 million.
Fiona Ambrose, secretary of the Stratherrick & Foyers Community Trust, said NBW was still negotiating from an offer of £2000.
She said: "The Trust would want a greater sum [than £2000 per hour]. NBW are out of step."
Corriegarth was owned by Andrew Fraser, but in April he transferred parts to Alexander Albert Henry Fraser, understood to be his 29-year-old son, for no charge.
Highlands SNP MSP Mike MacKenzie said: "The No campaign's new donors will do little to win friends for the anti-independence campaign if their track record in these communities is anything to go by."
Since its launch in June 2012, Better Together has received £2.7m in donations - £1.1m in the period to April this year, and £1.6m since.
NBW spokesman Graham Irwin said the £2000 per MW offer had been part of the Corriegarth plan throughout, but otherwise refused to comment.