danny - // AH, There must be some nefarious reason for this sudden spate of admitting to being junkies. //
I believe the driving motive is the attention of the press - the closer any of them get to the top of the pile in the PM race, the harder and deeper the press look at them.
If you have a secret, it's far better to get your admission in first, because an admission can be spun as 'honesty' whereas a discovery by the press will always be a 'cover-up' and dishonesty is often death to a political career.
I am still cynical enough to think that there is a cachet to being seen as being a bit 'edgy', and let's face it, the Tories are hardly known for that are they?
If the Tories, and the nation want 'something that is not Teresa May' - this may be some of the candidates' method of announcing that they fit the bill.
Let's face it, fessing up to being partial to a bit of gak certainly beats running through a cornfield in your list of top ten naughty things to do!