OK, so Local LCC groups won't have the influence to change this. Surely this is where the central group should be getting involved too? In a "this isn't juat a local issue to you, you need to get this right, and the whole of london cycling is now watching you" sort of a manner. Councils hate big outside groups watching them do things, and do change things because of that....
I can't see that LCC in Merton have so far grappled with the Rediscover Mitcham plans. I will draw their attention to it.
It is quite possible for this type of 'regeneration' scheme to go through without much transport scrutiny. In the consultation lots of people said they wanted more car parking very few mentioned cycle parking. So the plans have given them more car parking! At first glance some of the cycle facilities look half a****d and discontinuous at tricky junctions. Having a two way cycle track beside a one way motor road is known to create conflict at junctions. Personally I like the idea of opening up a bus and cycle street but I would have to know the area well to be sure.
Oliver is right about local relationships and local knowledge being the basis for getting local influence. Building relationships is a long game, but very well worth it. The key is to get accepted so that your local views are considered before and while they draw up the plans.
LCC doesn't have the resources to jump in and quickly identify the flaws in all such schemes, most of our knowledge and campaigning power lies in the volunteers at local level. We try to use our networks to support groups with expert knowledge and share practical advice.