The structure was built in 1830 as an observatory and folly

Clavell Tower sits just metres from a ledge at the World Heritage site of Kimmeridge Bay, Dorset, but could soon fall into the sea due to erosion.

Purbeck District Council has approved a plan by The Landmark Trust to move the former observatory 25 metres inland.

The project has received about �600,000 in lottery cash and fundraising but about �114,000 still needs to be found.

Work is expected to begin in late spring and could last about 18 months.

A Landmark Trust spokeswoman told the BBC News website: "We are still fundraising and providing we raise all the funds, work should commence in spring.

"We have raised about 84% of what we need. We still have �114,000 to go and the last bit is the hardest."

Wessex Poems

The Landmark Trust has taken on an indefinite long lease of the site from the tower's owner, the Smedmore Estate.

The trust said if work does not start soon and more erosion takes place, health and safety regulations may prevent anyone from working on it.

Thomas Hardy used to take his first love, Eliza Nicholl, to the Tuscan-inspired structure and used a picture of it for the cover of his Wessex Poems.

PD James used the haunting building, derelict since it was gutted by fire in the 1930s, as the setting for her novel, The Black Tower.

The historic structure was built by the Reverend John Richards Clavell of Smedmore in 1830 as an observatory and folly.

Anyone who wants to make a donation can call the Landmark Trust on 01628 825920