The Early Childhood Forum, a coalition of 60 early years organisations, is pressing for a meeting with ministers.
In a paper ahead of the second reading of the Academies Bill in the House of Lords last week, the group said they were 'extremely concerned about the impact of the Bill on the education and care of very young children, under the Early Years Foundation Stage'.
They said it is not clear what will happen to the curriculum for threeto five-year-olds in nursery and reception classes and stressed the need for all providers of education and care 'to provide the balance and age-appropriateness that the EYFS offers.'
The forum's spokesperson, Patricia Durr, said, 'There doesn't seem to have been much thought given to threeto five-year-olds, and lots of children in nursery and reception classes will be affected.'
She added, 'We don't want the focus on very young children's needs to be lost. There's nothing in the Bill to say that academies have to follow the EYFS. We want an amendment that would require academies to follow the EYFS.'
The paper said academies have not 'been evaluated specifically in relation to the experiences of young children and it is alarming that the expansion is being pushed through so quickly'.
The ECF is concerned that there is no requirement for schools that want to apply for academy status to consult parents, teachers and the local community.
They worry 'that the independence of academies will pull many children out of integrated structures under Every Child Matters', and ask what will happen to children's centres and extended services co-located at primary schools that opt out.
They also want clarification about what support and links academies will have to Children's Trusts and Local Safeguarding Boards, and about support for provision for children who have special needs.
Meanwhile, the campaign group 38 Degrees is urging people to write to their MP to support an amendment to the Academies Bill to ensure that schools seeking academy status will have to consult the local community.
For details go to http://www.38degrees.org.uk/page/speakout/academies