The government has decided that new mothers know best, as it prepares to announce proposals that will allow them to divvy up annual parental leave allotments with husbands or partners.
Nick Clegg, deputy prime minister, will announce on Tuesday that the UK will introduce a system of shared parental leave from 2015, in a move aimed at getting more women into the workforce and encouraging men to take time off to care for children.
Leaders of small businesses have attacked the proposals, which they say will cause "unnecessary friction" between parents and employers.
Under the plans, a mother will still be entitled to 52 weeks' maternity leave – three-quarters of it paid – but will be able to trigger flexible leave at any point after the first two weeks, either "chopping up" the time by taking it in turns with her partner or taking time off together. The only rule will be that no more than 12 months can be taken in total, with no more than nine at guaranteed pay.
In theory, a new husband could take a year off for childcare duties – by combining standard two-week paternity leave with the last 50 weeks of his wife's allotment.
Mr Clegg will say the reforms have the potential to transform opportunities for young parents considering starting a family.
"You won't get to 30 and suddenly have to choose – motherhood or work – because we're making the changes that will give you a route back," he is expected to say in a speech.
The deputy prime minister will also confirm plans to extend the right to request flexible working, at present available to parents of under-17s and some carers of adults, to all employees.
To make the parental leave proposals more palatable to businesses, the coalition has dropped a plan to offer fathers a guaranteed extra month's paid leave – a "daddy month" – in addition to the current two weeks' paternity leave.
However, Mr Clegg will say that flexible leave will be reviewed by 2018, when extending paternity leave will be looked at.
The concession only partly assuaged business's criticisms. Adam Marshall, policy director at the British Chambers of Commerce, said the proposals would "risk causing unnecessary friction between parents and employer, and raise unrealistic expectations about the level of flexibility most businesses will be able to accommodate".
"Allowing chunks of maternity and paternity leave of as little as one week to be taken will place a disproportionate strain on small firms and will be very complicated to administer," added John Walker, national chairman of the Federation of Small Businesses.
Mr Clegg's aides said employers would be able to veto unreasonable proposals for splitting up the leave in small chunks.