https://www.caa.co.uk/WorkArea/Downl...?id=4294975950
Questions on tobacco smoking refer. ( Box 29)
The Declaration refers.
Common sense dictates the truth.
If you want to chase the matter up further then research the CAA medical site to see how long you can fly after a diagnosis of lung cancer or bladder cancer. The fact that you've smoked for a little while probably won't bother them at all.