No as i've got rid of all the plants now! my fellow allotmenteers don't seem at all worried by it when i showed them??? said its probably nothing and that they have been attacked by the cold! which i suppose would make sense but im not convinced as it looked so much like white rust! and why has'nt anyone elses died? they had been hardened off for at least 2 weeks!
They also said cabbages were ok, just watch and wait!