The trust had agreed terms to buy Prior's Wood and Bourton Combe, part of the Tyntesfield Estate near Bristol, with plans to open them to the public.

But the bid collapsed after an application for nearly £1m in lottery funds was rejected by the Heritage Lottery Fund (HLF).

The HLF said it could not fund every bid, and that this one did not meet its criteria.

'Another £300,000'

The trust had raised £40,000, and still hopes the HLF will help buy Bourton Combe.

Steve Grainger, chief executive at the trust, admits the purchase would have taken too much money from the regional pot.

"We had asked for almost £1m... and the HLF knew we would probably need another £300,000 to make the woodlands safe for public access."

The National Trust bought Tyntesfield House in summer - but not all the accompanying woodland.