The groundbreaking intelligence work carried out at Bletchley Park during the second world war was credited with bringing forward the end of the conflict.

In 2011 the site was awarded a £4.6m grant from the Heritage Lottery Fund (HLF).

But Bletchley is currently in the throes of a bitter dispute, between owners who want to create a brand new visitors centre, and volunteers who have been working on the site for years.

Jeremy Cooke reports.