As always, common sense prevails. I am sure someone has been caught about to drive off, over the limit, and has pleaded "but I was just getting something out of the glove box,I knew I couldn't drive, and had no intention of driving". If the police, or anyone else thinks someone is about to drive off, drunk, they should stop them from doing so.They will have their day in court to protest their innocence. If they really had to return to their car to collect something important, like medication, that will be the defence, and you will be expected to provide some evidence. It is clearly nonsensical to suggest that possession of car keys alone could result in prosecution. Most people keep all sorts of keys in their possession, keys to several cars, workplaces,pcs, homes- no-one would suggest that when you were falling out of a club rat-arsed at 5am you intended to use them. If, however, you staggered to your car and sat in the driving seat, it would be reasonable to assume you intended to drive home. For the prosecution to succeed, the police have to provide two things: the criminal act, and the intention to commit it.If you can provide evidence that one or the other did not apply to you, you are home and dry. The criminal act in this case is sitting in the driving seat of a car drunk, all you have to do is persuade the beak that you did not intend to drive.