Just to expand on what I meant - there were a few throw in there comments - unsubstantiated !
The weight of research in psychology says that working mothers and going to childcare places (wherever - but obv. some better than others!) are unlikely to harm a child's attachment so long as the child receives good responsive and sensitive care from the parents.
So, the point I was almost making was that the attachment with 'a' person, generally a parent must be good and if it is and the childcare setting is quality then no worries. What I think the govt are trying to tackle is when mothers feel they HAVE to work for economic reasons, because if a mother has a negative attitude to working because they feel forced into it / are depressed, then there is a danger here that the child will develop negative feelings about childcare, and then themselves, and this may affect their attachment etc.
So, if the government are going to give those mothers who have are 'forced to work' and have a negative attitude about work, the ones who probably will manifest problems, the chance to stay at home, then great !
If you are interested in these studies:
How Mothers attitudes to work matter - Lois Hoffman (1989), Crockenberg & Litman ( 1991), Hock 7 DeMeis (1990), Belsky & Rovine (1988)
Parents attitudes / type of care received - Broberg et al (1997), NICHD Early Child Care Research Network, (1997)
Longer Leave being better to help depression etc - Clark et al, 1997