The thing I don't get about all this bashing part timers is that a woman's career covers something like 40 years. The child rearing years take up just a small portion of that.
If a mother (or father) wants to be there for the children during those years and not take on the commitment of full time work, then there are many advantages to working part time.
For women, a great excuse for the lack of opportunities and progression has always been the poor provision of childcare. Fair enough, if you're earning a small fortune, working full time is an option, as you're far more likely to be able to afford full time childcare. The same for parents with great family support.
For the vast majority of workers earning minimum or even average wage, the tax credits go someway to helping parents to work and pay for childcare.
I personally think that has many benefits for women and society as a whole. For parents, it means they can take the pressure off a little during those early years whilst keeping their hand in the workplace. Or it enables them to improve their education for better employment prospects in the future, when their children are older.
For single parents that benefit is surely enormous. The alternative for most single parents would be to stay on benefits completely and not work at all, as childcare costs would be prohibitive.
The system may well need tinkering with, I wouldn't argue that it's perfect, but the principle behind it is spot on.