1. This article dealing with Labour policy on corporate governance from (!) 1996 shows that actually there was some quite radical thinking going on immediately prior to Government. No reason why we shouldn't be as ambitious now, especially given a) the experience of the financial crisis and b) having had a seriosu crack at pretty manistream governance reform when in power.
2. This paper is worth a look. Not the first one I've seen that seeks to query the motives of union shareholder activism. Don't think these would appear if it was ineffective.
3. The Fair Pensions report on ethical funds is worth a read, low priority given to labour issues is notable.