Hundreds of Sure Start centres face closure this year and thousands of others are cutting services and have warned of job losses, according to a new report.
The closures and reduced services, caused by Government cuts, could see 60,000 families lose their local centre, it is claimed.
A study by families charity 4Children and the Daycare Trust suggests 250 Sure Start Children's Centres are expected to close, 2,000 will provide a reduced service and 3,100 will have a smaller budget.
Staff at 1,000 of the centres - which offer a range of services to families with young children, including help for parents wanting to find work - have been warned about the threat of redundancy, according to the survey of almost 1,000 centre managers across England.
Anne Longfield, chief executive of 4Children said: "Families across the country, particularly the most vulnerable, depend on Sure Start Children's Centres to help get their children off to the best start in life. We know that local authorities have some extremely difficult spending decisions to make but investment now will lead to real savings in the long term.
"Local authorities need to find new ways to ensure Sure Start Children's Centres earn their keep by allowing them to become genuine hubs for all children and families services in communities, reducing replication and improving impacts. Voluntary and community organisations stand ready to help councils find innovative solutions to these funding dilemmas."
Anand Shukla, acting chief executive of the Daycare Trust, said: "Behind every children's centre facing closure is a community of families devastated at losing one of their most valued local services."
Labour MP Frank Field, an adviser to the Government on poverty and life chances, said: "It is inconceivable that we can make the foundation years effective if Sure Start Children's Centres all over the place are being slaughtered. Local authorities must seek to employ innovative methods to ensure families - especially the poorest families - do not lose the vital support they need."
Children's minister Sarah Teather said: "Sure Start is at the heart of our vision for early intervention - that's why we have ensured there is enough money in the system to maintain the network of Sure Start Children's Centres, as well as providing new investment for health visitors.
"I understand that local authorities are facing difficult decisions which require local discussion and hard choices. Many areas haven't yet made final decisions, but what's important is that communities have access to services that support children and families, particularly the most disadvantaged. The new Early Intervention Grant gives local authorities the freedom and flexibility to make the best decisions for the families in their communities."