A quarter of families make use of grandparents for childcare each week
Grandparents who care for grandchildren should be paid tax credits and given "granny leave" if they work, a charity report has said.
Grandparents Plus says grandparents are playing an increasing role by caring for children and supporting parents.
And a survey for the charity found four out of 10 parents were likely to seek more help during the economic downturn.
Children's Minister Beverley Hughes said government research suggested most grandparents did not want to be paid.
The report said parents who were able to return to work because of childcare by grandparents should be able to claim tax credits.
Grandparents in work should have two weeks' "granny leave" in the child's first year, it added.
The report called for employers to ensure they extended flexible working practices to grandparents.
And it said working grandparents providing childcare should get credit towards their National Insurance in the same way that parents, foster carers and carers of disabled adults will be able to from April 2010.
Grandparents Plus chief executive Sam Smethers said: "We believe that the existing policy focus on the nuclear family means we miss what is really going on.
"In the tough economic climate it is families who are taking the hit. Grandparents are playing an ever-increasing role in supporting family life and caring for children but their contribution often goes unrecognised."
The YouGov survey for Grandparents Plus of more than 2,000 people found 61% of those polled agreed that grandparents should be paid by the government for providing childcare.
Three-quarters said that grandparents of working age who provide childcare should get credit towards their state pension.
Some 55% said that grandparents should have the right to request flexible working in the same way as parents who have children aged under six.
The figure for those who were more likely to turn to grandparents to help with childcare in the current economic climate rose to 55% for parents aged 18-34.
Ms Smethers said: "Our poll shows that the general public appreciates the important role that grandparents play but most people do not think the government values this highly enough. It is time to recognise the contribution grandparents make."
Ms Hughes will launch the Rethinking Family Life report at the House of Commons on Wednesday.
She said the government recognised the "valuable role" grandparents played in providing childcare but that intervention in informal family arrangements "would be going too far".
"We would not wish to disturb family arrangements by encouraging charging between family members who would not otherwise have done so," she said.
"And we believe that many people using relatives for childcare would not welcome such interference either.
GRANDPARENTS IN THE UK
14 million in total
3 in 10 grandparents are of working age
Grandparental childcare is worth £3.9bn
1 in 4 families use grandparental childcare each week
1 in 2 single parents rely on grandparental childcare
Source: Grandparents Plus
"Research shows that, in general, most grandparents do not want to be paid for the care they provide."
Shadow families minister Maria Miller said: "Gordon Brown keeps telling us that the state has more of a role to play in helping people through the recession but this report clearly shows that it is often families that we turn to first for support and guidance during tough times.
"Grandparents often play a critical role in providing the flexible childcare, emotional support and financial help that families need."
Saga's editor-at-large Emma Soames said the magazine welcomed the report.
She said: "Many parents, particularly younger single parents, are highly dependent on grandparents for childcare and financial support.
"The government needs to support grandparents who provide unpaid childcare for their families.
"Where grandparents are foregoing the right to work and suffering financially to support their families it seems fair and right that their role should be acknowledged."