The Labour MP Stella Creasy is threatening to take legal action after being told she cannot hire a locum to cover her maternity leave after the birth of her second child. Creasy’s pre-action letter to the Independent Parliamentary Standards Authority (Ipsa), which regulates MPs’ pay and expenses, comes as a bill to enshrine the right of flexible working in law is introduced into the House of Commons this week. The MP for Walthamstow, who is seven months pregnant, became the first to use a pilot providing full locum cover for her first child but has been told she cannot have the same arrangement for her second. Ipsa told her the request was “misconceived”, adding that the core parts of an MP’s job “cannot – in legal and constitutional terms – be undertaken by someone else”. Ipsa has offered the MP £35,000 to cover extra costs over seven months to pay for staff who would be expected to “escalate matters to the MP”. Earlier this year, the government pushed through a bill giving ministers access to six months’ maternity leave on full pay. Creasy said full maternity cover for MPs was vital to reassure constituents while their MP was taking leave. “Either my constituents will be short-changed or my baby will lose me for six formative months – this would be illegal in any other real workplace setting,” she said. More than 30 charities, campaigners and business groups have signed a letter to Ian Todd, the interim CEO of Ipsa, calling for him to overturn the decision. Joeli Brearley, the CEO and founder of Pregnant Then Screwed, who is supporting the campaign, said: “Parents need time to bond with their baby and women need time to recover from childbirth; this decision means that an MP can do neither. This is bad for democracy and for equality.” A spokesperson for Ipsa said an additional senior staff member to cover MPs’ absences would be able “to fulfil all possible duties”. “Constitutionally, no one can take on the full roles and responsibilities of a member of parliament, who is an office holder elected by the general public,” they said in a statement. “It is up to parliament to decide if the law should be changed.” Labour’s Tulip Siddiq is to present a cross-party flexible working bill before parliament on Thursday. Data from the Pregnant Then Screwed helpline shows two-thirds (71%) of requests for flexible working were rejected in the first year of the pandemic. The bill, which has cross-party support and the backing of campaign groups and unions, would give all workers a right to flexible working from day one and make employers highlight flexibility in job adverts. More than 5,000 supporters have written to their MPs to encourage them to support the 10-minute rule bill. Employees only have a right to request flexible working, but businesses have no obligation to accept. The Conservative manifesto promised action on flexible working, and the government recently promised a consultation later this year. Siddiq said despite a misconception that the pandemic had transformed flexible working, there had been declines since March last year, with lower income workers less likely to be allowed to work flexibly. “The current law is outdated and we need new legislation to make flexible working a right for all rather than a perk for the few,” she said.