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 can not 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 .
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 can not cope with more rights for employees .