Sorry for being off topic and not answering the OP, but having read some of the replies I just want to say that as a working parent, the 12.5 hours has helped me significantly.
I am extremely blessed to have twins (naturally conceived) but a less than desirable side-effect is that it doubled my childcare costs. When TTC we were working on the assumption we'd have a single child and planned and budgeted on that basis.
I am now a single parent and despite tax credits paying a proportion of the fees (for which I am hugely grateful), I have been struggling to find enough money to eat at times in the last three years. Now my children have turned three and qualify for the hours, it has eased some of the burden.
For everyone who thinks subsidised childcare is a waste of money I would ask how my being consigned to the ever increasing number of people on benefits would help? What example does it set to my children? My skills and confidence would atrophy making it all the more harder for me to get back into the work place and certainly not at a level I would be if I'd stayed. Subsidised childcare OTOH sets a great example about self-responsibility, allows me to continue to work and develop my career so that I will pay more tax back into the system. Also, I am still paying tax and while my childcare costs may be subsidised, that money is being used to pay the childcare provider, which in turn pays wages (and therefore tax) and benefits the local economy. And I am still paying tax on my own income. Over the course of my life, I will have paid out far more than I received. If I had no childcare and had to stop working, it would take me more than a lifetime to repay what I had claimed in benefits.
That said, I think the general cost of childcare could be brought down massively be cutting a lot of the needless bureaucracy generated by OFSTED and allowing children a much more informal style of childcare.