I can't imagine this ever flying anyway. First of all, if the "care group" uses the facilities for the afterschool hours/evenings or overnight (which is an awful idea IMO), there will be huge issues over who is responsible for what. I assume there is some sort of insurance on the buildings, which could be affected by subletting (which is what it would be) a large portion of hours to an outside company. The insurance would either go up or cancel and not be willing to cover.
And what about risks of theft and damage to not only buildings/school property, but to student/teacher property as well. Add in the health and safety issues, along with the extra cost of cleaning, utilities, staff, and food (as many schools don't have the equipment to do an evening meal which they'd need if they were running until any time after 6pm). There is no way on earth it would be affordable.
And what about the inconvenience to the school itself? Schedules would be disrupted (because childcare needs to be consistent or what's the point), so parents evenings, setting up in the afternoon for morning or next day activities, deep cleaning/repairs/refurbishment in the off hours or holidays is suddenly a whole lot more difficult.
Security is also an issue. In order to run this type of programme, people other than school employees are going to need keys and passcodes for the property. The more this info is shared, the more likely it's insecure. And if they leave a door unlocked or gate open, it's going to be a "who's fault is it?" issue.
And it doesn't matter if the "care group" rents the space for the afternoon/evening, if someone gets hurt, the LA is going to end up being sued, deep pockets and all, because they are technically the owner of the building. And I highly doubt the LA wants to open themselves up to this.
If the government is so concerned about safe affordable child care in off hours, why don't they work on making more safe affordable childcare available in general? There's absolutely no need to use school buildings. IMO this is just (as someone else has already said) to soften everyone towards the idea of longer school days. They need to stop trying to make school be "work-friendly" and fitting it into work hours and start working on what's best for the children.