Parents in England should be able to access more childcare on the premises of their child's school, ministers say.
The government is cutting red tape to enable schools to offer affordable after-school and holiday care, working alone or with external providers.
Ministers also want to make it easier for parents to use informal childcare, by increasing the number of hours permitted each day from two to three.
The Family and Childcare Trust said it was "underwhelmed" by the report.
The report - More affordable childcare - is based on the government's Commission on Childcare which took evidence last summer on how to overcome the barriers to parents accessing care.
School sites and friends
It says obstacles to schools setting up on-site childcare must be removed, and so ministers will abolish the duty on maintained schools in England to consult when offering out-of-school-hours provision.
To make it easier for schools and childcare providers to work together to offer activities, the government says it will bring forward legislation so that childcare providers can work in several locations, for example both in a nursery and on a school site, without needing to register each site separately.
The report says: "Schools are central to their local community, trusted by parents.
"The full potential of school sites is not being realised. Schools are well-placed to expand affordable provision.
"Making school sites available to other providers could generate savings, which could be passed on to parents through lower fees."
Ministers also pledge to support parents who make informal childcare arrangements with friends and families.
Currently, parents can pay family members to care for their children, without the family member registering as a childcare provider.
But if they want to pay non-family members, like friends or neighbours, to care for their child (on a regular basis and for more than two hours a day) that person must register with Ofsted.
"We intend to encourage informal childcare by raising the threshold so that the requirement to register with Ofsted commences after three hours of regular care, rather than two," the report says.
The report also says the government plans to remove planning restrictions for nurseries allowing them to expand, for example by using vacant office space.
And, from September, local authorities will no longer act as gate-keepers to early years funding for those childminders and nurseries judged by the watchdog, Ofsted, to be good and outstanding.
The report says there is a "strong case" for removing the staff-to-child ratio and staff qualification requirements for providers of "wraparound" care for children in full-time education.
"This would address a current inconsistency which is that these children spend most of their day in school in much larger groups than the current 1:8 ratio for childcare permits.
"For children in full-time education, the focus of requirements of childcare, outside the school day, and the responsibility of the staff caring for them, should be ensuring their safety."
Ministers are also removing the "unnecessary after-school learning requirements" for reception-age children - childcare providers for these children will no longer have to meet the early years foundation stage learning and development guidelines.
Education Minister Elizabeth Truss said: "Schools can do so much more to increase the supply of trusted, high-quality childcare at a price families can afford. Until now red tape has prevented them from doing so.
"Our reforms today change this and will let schools offer high-quality before and after-school childcare as well as during the holidays - all in a trusted environment.
"These reforms will mean that ordinary nurseries will also find it easier to expand and even find new, bigger premises."
The proposals are the latest move by the government to reform childcare.
Earlier this year it was forced to ditch reforms relaxing the rules on the numbers of youngsters that nursery staff and childminders could care for.
Deputy Prime Minister and Liberal Democrat leader Nick Clegg blocked the childcare ratio plans, later saying that the proposals were widely opposed by parents and experts, and could have pushed costs up.
Costs for parents
The report comes after a report this week from the Family and Childcare Trust warned that more children could be left home alone this summer because of rises in fees and a shortage of places.
Anand Shukla, chief executive of the Family and Childcare Trust, said his organisation was underwhelmed by the report.
"Our recent research into holiday childcare costs revealed that prices have broken the £100-a-week barrier for the first time across Britain, against a backdrop of stagnant or low wages, and we're not clear how these proposals are going to make meeting those costs any easier for working parents.
"We understand there will be a further announcement about childcare costs this week, and in it we hope to see some solutions that address the widening gap between childcare costs and wages."
Anne Longfield, chief executive of the charity 4Children, said: "4Children has advocated more school based childcare for 30 years because we know that parents value the certainty and support that it can provide.
"Schools buildings are important community resources but too many still shut their doors at 3.30pm."
"Moves towards reducing bureaucracy and making it easier for schools to provide childcare are welcome and the emphasis on schools working with voluntary and community groups is also positive.
Nansi Ellis, head of education policy at the Association of Teachers and Lecturers, said: "The government is right to prioritise making childcare accessible how, where and when parents need it and at a price they can afford. But the needs of children must not be sidelined.
"The government must ensure the quality of care is not sacrificed to cost, that buildings are fit for young children, with accessible toilets, suitable areas for eating, and outdoor play, and that those who work with young children are well-qualified to meet their range of different needs."