The report, by British charity Grandparents Plus and government body the Equality and Human Rights Commission, highlights that grandparents of the families who were most at risk of poverty were under increasing pressure to take on a caring role.

The Protect, Support, Provide report warns that various government actions on tackling poverty actually conflict with each other. The government's aim of increasing the number of lone parents in the workplace led to increasing pressure on grandparents to step in at home.

Many who retire early to take on the role of child carer do not receive a basic state pension, as they were unable to accrue a sufficient number of credits when they were in work. Chancellor Alistair Darling acknowledged the increasing role of grandparents in family life and tried to address the problem within the 2009 Budget.

He announced that from April 2011 grandparents who look after under 12s for 20 hours or more a week would be given credits to gain a basic pension.

A spokesman for the UK's Department for Work and Pensions said, "We do expect lone parents to do more to prepare for work because we know that work is the best route out of poverty.

"However, we’ve made it very clear that we only expect parents to do this during school hours or during the hours they are entitled to free childcare.

"We absolutely do not expect grandparents to subsidise this work."

However, the report's authors do not believe enough is being done.

They called on the government to find a balance between supporting employment through additional childcare places, flexible working hours and providing adequate financial and practical support.

Chief Executive of Grandparents Plus, Sam Smethers, said, "until very recently we’ve seen a failure to consider the importance of grandparents in family life.

"This has made them invisible to government, so it’s not surprising that targets on child poverty and older people’s poverty are working against each other."

Commissioner at the Equality and Human Rights Commission, Kay Carberry, added, "the contribution of grandparents cannot be ignored.

"Without the free child care they give, many parents would not be able to work.

"This is particularly important in low income families that may find it difficult to pay for childcare."