Theresa May is throwing down the gauntlet to her successor, pushing for fathers to have more time with their newborns. Writing in the Guardian she says she hopes that better paternity leave and time off work to care for premature infants will be one of her lasting legacies as prime minister.

She says the status quo is holding back women and reinforcing the gender pay gap.

She writes: “More often than not it is the mother who cuts her hours or opts to works flexibly, the mother who decides not to go for promotion, the mother who stays at home when the child is ill.

“Much of the gender pay gap can be traced back to the balance of childcare responsibilities, while the lack of women in senior positions is partly caused by the fact that mothers, much more than fathers, are too often expected to juggle careers with caring.”

May says that division is not inevitable but that policy is “not sending fathers the correct message when our current leave allowances give women 26 times more leave than men”.

On Friday the government will launch a consultation on changes to parental leave entitlements, one of May’s last acts as prime minister and which will have to be enacted by her successor.

The proposal envisages a longer period of paternity leave as well as a new neonatal leave entitlement for parents of premature and sick babies who need to spend a prolonged period in hospital.

May says she believes the choice offered to parents by shared parental leave was gradually starting to shift societal attitudes about who should stay home with a baby, but that the slow uptake makes it clear the government has to go further.

“All too often it is still mothers, not fathers, who shoulder the burden of childcare. So it is clear that we need to do more. The UK has some of the most generous maternity leave allowances in the world, but we only guarantee new dads and same-sex partners a fortnight off work – making it harder for them to bond with their child and care for their partner, and implying that it is the lot of the mother to be the primary caregiver.”

May says giving fathers longer leave and better pay to spend time with their newborns will not only benefit children but equalise men and women’s roles both at home and in the workplace.

“Caring for children is a shared responsibility and means that employers will not be able to make assumptions about who will take on childcare responsibilities when a couple starts a family.”

She says she was deeply affected by a visit to Alder Hay Children’s hospital when she met parents whose babies had been born prematurely or suffered complications, and the fathers were worried they would need to return to work before their newborns got home. “That’s not fair and it’s not right. These are issues close to my heart and I’m proud that today’s consultation – the next evolution of the shared parental leave policy that I started long ago – is one of my final acts as prime minister.”