I think a bit of self-preservation is called for.
If you get to the junction first, then put yourself in a very strong primary position, so that no-one (car, truck, bus etc) can pull alongside your rhs.
If there are already vehicles stopped at the junction, irrespective of what type of vehicle it might be, DON'T feel tempted to cycle up the inside, even if there is a cycle filter lane and an ASL. You have no idea what frame of mind the driver at the front of the queue is in: he might be half asleep, on the phone, in a tearing hurry to get his load dropped off. Better to be safe than sorry. Stay in the traffic lane, in primary, and wait your turn. You're better off behind a truck, than in front of it.
That's not to say I don't fully support the concerns in this thread, and I will be writing to my MP. But it will take ages for anything to happen, and in the meantime I want to stay safe.