Older foster children have been thrown a security blanket after the Government announced they will be given the opportunity to stay with foster parents until the age of 21.
Foster parents are currently only given financial support to look after children until they are 18.
Under a new law, local authorities will have a legal duty to give families financial help for every young person who wants to stay with their foster parents until their 21st birthday.
Children and Families Minister Edward Timpson, whose own family fostered nearly 90 children, said: "I know from the many foster children I grew up with how crucial it is for them to be given sufficient time to prepare for life after care.
"A growing number of local authorities already offer young people the choice to stay but with little financial support it can be challenging for their foster families. Now all councils will have to follow their example."
Children's rights campaigners welcomed the change, which reflects growing evidence that removing support at 18 can impact on vulnerable young adults' likelihood of staying in education and finding work.
Robert Tapsfield, chief executive of the Fostering Network, said: "We are absolutely thrilled with this change in legal duty for local authorities, backed up with appropriate financial support, that will ensure that young people in England have the opportunity to enter adulthood supported by the foster families that have devoted their lives to caring for them."
Last year only 330 young people (5 per cent of care leavers) in England were still with their foster carers by the age of 19.
Government projections in early 2012 suggested this new measure would initially lead to about 530 extra young people a year staying on in care annually.
But the funding announced has allowed for more than ten times that number after local authorities and campaigners expressed concerns that the Department for Education had under-estimated interest.
The announcement only applies to children in England, as the issue is devolved in Scotland and Wales and they have yet to raise the age of support.