The Forestry Commission has confirmed that this diseases has been found on Lawson Cypress trees in Devon. For more detail see the FC website.
This is another variant of the diseases P. Ramorum and P. Kernoviae which have been associated with attacks on larch trees and also on bilberry & heather. It is something that I am keeping a close eye on as these diseases have the potential to cause the loss of heather on a large scale.