If you care enough about it, do something yourself! The way you talk about the unions, as something outside yourself, I'm guessing you're not a member, or you're a totally passive member. If the former, why do you think the unions should be doing anything to help you? And if the latter, how do you think we can do anything without action from our members?
If you are a union member, and you don't think your union is doing enough, then rally your colleagues and petition for action. The unions are democratic organisations, but it can't work as it should if people just sit on their arses waiting for somebody else to do the hard work.
To be honest I thnk the change in the law is a step n the right direction, and I have been on both sides of the fence. Ie a wronged employee and a lawyer working on behalf of a business being sued on very thin grounds be former employees. In practice I doubt it will make a lot of difference as you can sue for sex discrimination etc from day 1 and low earners will be exempt from the charges.