The National Trust is contacting 200,000 members and previous donors with a direct mail campaign to raise urgently-needed funds for coastal heritage projects on Brownsea Island off the Dorset coast.

Created by marketing agency TDA and landing this week, the appeal highlights how Brownsea Island is at the mercy of the sea, explaining how and why the National Trust wants to protect its history.

A campaign microsite, also created by TDA, gives more detail to the story and includes video vox pops as well as walk suggestions and photographs.

Supporters are encouraged to engage with the appeal online, submitting their own pictures and memories of the island.

"We have carefully timed this campaign to reach supporters during the summer when they may be visiting coastal sites in the UK, or remembering seaside trips they have taken with their families in the past," said Bex Lewis, senior account manager at TDA.

"This brings additional 'warmth' to the environment for the appeal, enabling the proposition to have greater resonance."