text: Labour would introduce a new legal right to ‘granny leave’ to allow working grandparents to take time off to help care for their grandchildren. The party’s deputy leader Harriet Harman, in an interview with the Daily Mail, said grandparents would be allowed to take up to four unpaid weeks off per year in order to help with childcare. She said the policy, to be unveiled in Labour’s women’s manifesto, to be launched today, would require a change in the law and would help millions of working families. Scroll down for video . Labour's deputy leader Harriet Harman (pictured) said grandparents would be allowed to take up to four unpaid weeks off per year in order to help with childcare . More than half of mothers rely on grandparents for childcare when they first go back to work after maternity leave, and two-thirds of grandparents with grandchildren aged under 16 provide some childcare. Research suggests 1.9 million grandparents have given up a job, reduced their hours, or taken time off work to look after their grandchildren. But the proposed extension of workplace rights to millions more staff is likely to meet with a backlash from some business leaders, who will have to bear the costs of absences. They are already having to implement a new system of shared parental leave, which allows mothers and fathers to swap their time off after a new child. Critics will argue businesses cannot be expected to cope with more rights for employees as the economy recovers from the recession. Miss Harman insisted many businesses would welcome ‘granny leave’, since it would be likely to keep more older women in the workplace – and also enable their children have a better work-life balance. She said she envisaged many grandparents using the new legal right to take time off over school summer holidays, when parents otherwise have to pay for expensive childcare. ‘In many families, grandparents play an integral part of caring for their grandchildren and for many people that’s a financial necessity,’ she said. ‘But many people are working longer and today’s generation of grannies are working until they’re 67. They don’t want to have to choose between carrying on with their job and this role they regard as so important in their lives, which is their role with their grandchildren. ‘More and more daughters and daughters-in-law are in work, childcare is more expensive and grandmothers are now working. ‘Instead of having to choose between retiring early and giving up work, or not being part of the daily care for their grandchildren, we’re saying let’s look at the leave arrangements to recognise what the pattern of family life. ‘This is the next frontier. It’s the first time there has been a policy which recognises this role of grandparents.’ Miss Harman says a Labour government would legislate to allow grandparents as well as parents, or those with legal responsibility, to access the leave . Currently, parents can claim 18 weeks unpaid parental leave - of up to four weeks in any given year - per child up to their fifth birthday, soon to be extended to their eighteenth birthday. Miss Harman says a Labour government would legislate to allow grandparents as well as parents, or those with legal responsibility, to access the leave. Employers would not have the right to turn down the requests for time off. Sam Smethers, chief executive of the charity Grandparents Plus, said: ‘Grandparents are the hidden army of carers in Britain today. 'We know that one in five working parents – two million of them - would give up work without grandparents to rely on. But increasingly grandparents are working too. ‘So this policy is also a win for employers as it helps both parents and grandparents stay in work.’ Other measures in today’s manifesto will include doubling paid paternity leave from two to four weeks, and increasing the amount paid from just under £140 a week to £260 a week. The party also plans a controversial move to introduce ‘compulsory’ sex and relationship education in schools. Labour would change the law if it wins the election to force all state-funded schools, including primaries, to put sex education on the curriculum. Labour sources say ‘age appropriate’ teaching about sex and relationships would begin in Key Stage One, when children are aged five to seven. Parents would retain the existing right to withdraw their children from lessons on the subject until the age of 15. The party will also pledge today to crack down further on domestic violence by appointing a new commissioner to direct policy to tackle abuse.
target: Deputy leader Harriet Harman said policy would help millions of families .
  But proposal is likely to meet with backlash from some business leaders .
  Critics will argue firms cannot cope with more rights for employees .