I've tried to keep things separate.
I set out a detailed explanation of how I understand the relevant legislation.
I put forward a possible explanation as to why the Met has published this advice.
Although my practical experience is receding (like my hair) to the point of being a distant memory (like all sorts of other things) I've reported countless traffic offences in the days when that was what young policemen did. I've spent endless hours getting a shine on the seat of my trousers on courtroom benches waiting to discover I wasn't needed to give evidence after all. I've spent a lot of time doing court security as well. Plenty of opportunity to see how the system operates. With more experience I've marked up files of evidence and I'm old enough to have done a fair bit of prosecuting (only in magistrates' courts, of course.)
Based on that experience, I've tried - and apparently failed - to give a bit of an insight into the system. If you don't like it, fair enough. I'm in no position to change it.
Thanks for pointing out that the CTC has a policy on ASL's. I never doubted they would have one. I'd be more interested in a link to a policy about the use of video evidence to support prosecutions and even more to the point, any clear signs they they intend to do something positive about it.
Edit to add.
I've had a look through the CTC policy document on ASL's and a few things attracted my attention:
The relevant legislation is the Road Traffic Act 1988, section 36 and the Traffic Signs Regulations and General Directions 10, 36(1) and 43(2).
I think that's exactly the same legislation as quoted by the Met message.
Even places making extensive use of ASLs encounter problems with drivers encroaching on both the reservoirs and approach lanes. The police have the power to enforce ASLs, but often claim that it is a difficult task unless an officer has witnessed a driver cross the first stop line on a red light. .Proper enforcement, however, and amending the regulations to make it clear that ASLs are legally enforceable, would ensure that cyclists are more likely to benefit fully from these facilities, as would adding the contravention to the list of offences that may be civilly enforced.
I think this misses the point, or at least the point as I understand it. Enforcement of RLJ type offences by witnesses rather than cameras, needs evidence that the witness saw two things at once ie the colour of the traffic lights and the position of the vehicle in relation to the STOP line. It is possible of course - it's something we do all the time without a thought - but when it gets to proving it, it's easy for even a half-decent advocate to create a fog. That leaves clear-cut offending, ie disobeying the signs when they have been at red for a litle while. I'm at a loss to understand the bit about amending the regulations to make it clear they are legally enforceable.
As for the future, and the changes being considered for 2014, I've no idea what a "gated" entry for cyclists might be. No doubt it's a theoretical gate rather than something on hinges but I'm none the wiser. What seems obvious to me is that the regulations should be reworded to say that the first line does not apply to pedal cycles, alternatively, that only the second line applies to pedal cycles. The biggest advantage of that, apart from being easily understood, is that it would permit cyclists to ride on the part of the carriageway they considered safest.
Re the Mischief Rule. IMO there's no problem with interpreting the law here (so long as you are prepared to plough through it.) The intention of the legislators and those who wrote the supplementary regulations is as clear as can be. If people don't like it, they should lobby for a change in the law.