A community trust has been allowed to mount a £4m buyout of the small island of Ulva off Mull despite its owner’s reluctance over the deal.

Roseanna Cunningham, the Scottish environment secretary, announced she would allow a community trust in Mull to try to buy Ulva, which has suffered decades of depopulation and unsuccessful attempts at regeneration by its current owner.

The North West Mull Community Woodland Company (NWMCWC), which already owns a large area of Mull as a community asset, now has four months to raise the £4.2m set by an independent valuer as the fair price for the 1,860 hectare (4,600 acre) island.

Ulva sits on the west coast of Mull in the inner Hebrides, and has a population of only six, including its owner, Jamie Howard, who inherited the island from his mother. He is retaining a large house on the island, which is not included in the sale.

Howard put the island on the market last year for offers over £4.25m, with his agents highlighting its links to the authors Beatrix Potter and Sir Walter Scott, who used Ulva as inspiration for his poem Lord of the Isles.

Press reports said he hoped to earn £5m from the sale, which includes a pier head on Mull, numerous cottages, a little-used Grade II-listed church, a large country house and Neolithic standing stones. NWMCWC has been given the first right to buy the land, but Howard said he would have preferred to sell it on the open market.

The attempted buyout has proven controversial locally. Mull’s community council said last month it objected to the proposal, arguing that the money could be better spent on other projects and that all the islanders ought to have been consulted.

NWMCWC can apply for funding from the Scottish Land Fund, which has £10m a year to spend from the national lottery on community buyouts, but its single grants are normally limited to £1m per bid.

The woodland trust has already launched a worldwide appeal for funding targeting the descendants of migrants from Ulva, who include Lachlan Macquarie, a colonial governor of New South Wales, who has a university, bank and library named after him in Australia.

John Addy, a director of NWMCWC, said: “We are obviously delighted at this news which sets Ulva on a path of social and economic rejuvenation including repopulation.”