Half of all children in lone-parent families are now living in relative poverty, according to exclusive research that shows how a decade of austerity-driven cuts to benefits has left single parents among the most exposed to soaring inflation. In the first of a series of reports from the frontline of the cost of living crisis, the Guardian reports today on the impact of cuts to state support by successive Conservative governments, which have left women raising their children alone in a much weaker position to cope with the shocks of the pandemic and rising prices of basics such as food and heating. The vast majority of the 1.8 million lone-parent families in Britain – almost nine out of 10 – are headed by women. Together, they are raising 3.1 million children – more than a fifth of all children. Research shared exclusively with the Guardian by the Institute for Fiscal Studies sets out the scale of the crisis. It shows relative poverty for children in lone-parent families has risen at a significantly faster rate compared with other households. Relative poverty is defined as having an income of less than 60% of the national median, adjusted for household size. For single parents, this measure of poverty rose by nine percentage points between 2013-14 and 2019-20 to reach 49% at the onset of the global health emergency. In sharp contrast, the rate for children in two-parent families rose by only two percentage points to reach 25%. Tony Blair, the former Labour prime minister, warned that a “painful cost of living squeeze” was hitting families and that progress in tackling child poverty was severely undermined by sweeping benefit cuts imposed over the past decade. Eradicating child poverty by 2020 had been a key commitment made by Blair during his first term in government at the turn of the millennium. However, the study from the IFS suggests progress was reversed under the Conservatives amid the post-2008 financial crisis austerity drive. “The last Labour government made it a priority to tackle child poverty. Our policies revolutionised opportunities for lone parents by making work pay – lone-parent employment rose and child poverty fell sharply as a result,” Blair said. “That legacy has been undermined over the past decade as state benefits have been eroded, growth has been weak and wages stagnant, despite high employment rates for lone parents.” Figures from the charity Child Poverty Action Group show there were 3.9 million children living in poverty in the UK last year, more than a quarter of all children, or eight in a classroom of 30. Linking the growing divisions in society with the decade of austerity imposed by Conservative-led governments, the IFS said the rise in poverty for children living in lone-parent households “reflects reductions in the real value of state benefits in the years from 2011 to 2019”. Among the cuts in support that have most affected single mothers are the benefit cap, the four-year freeze in benefits between 2016 and 2020, the two-child limit and a lowering of the age of the youngest child when single parents must start looking for work. Before 2008, lone parents were able to claim income support until their youngest child reached 16, or 19 in full-time education. After changes first introduced by the last Labour government, and made substantially tougher by the Conservative-led coalition, this age limit was repeatedly cut. Now single parents are expected to prepare for work when their youngest reaches one, and then be in a job from the age of three. “Absolutely it increases child poverty,” said Morag Treanor, the professor of child and family inequalities at Heriot-Watt University. “Single parents don’t have the security to build what is required to search for work until they get their children into school or proper childcare. It’s very detrimental, it’s distressing and it has an impact on the mothers and the children.” With households across the country facing the worst inflationary shock since the 1980s, charities warned that single mothers were suffering a heavier toll from soaring energy prices and the rising cost of a weekly shop. Victoria Benson, the chief executive of Gingerbread, the charity for single-parent families, said: “The pandemic and the cost of living crisis have made their lives much worse, and the welfare system just doesn’t provide the necessary level of support.” She said the charity had heard of a single mother who doesn’t eat when her children are with their father, of a mum who didn’t eat anything apart from a single sandwich for three days because she had run out of money, and of food going off in fridges because it’s unaffordable to run the electricity. “This government urgently needs to do more,” she said. Laying bare the challenge for single mothers, separate research shared exclusively with the Guardian by the Joseph Rowntree Foundation showed that lone parents were more likely to be food insecure amid the cost of living crisis – with as many as 70% going hungry and skipping meals compared with 55% for non-lone parents. From a survey of about 4,000 people on low incomes, undertaken last month, the poverty charity said as many as 40% were unable to keep their home warm compared with 31% for two-parent families. Single parents were more likely to have taken on new debts, visited a food bank, and have gone without a bath, shower or basic toiletries. The IFS, which will publish a wider report into poverty and inequality later this month, also found flatlining progress in cutting absolute poverty rates for the children of lone parents, in addition to the rise in relative levels. Defined as income below a fixed poverty threshold, adjusted for inflation and household size, it suggested this was unusual after years of steady gains in the early 2000s. “Lone parents on low incomes are particularly reliant on income from benefits. These cuts to benefits have offset rising employment incomes in recent years, which have been large for lone parents,” it said. Experts said the benefits cap, first imposed in 2013, and the four-year freeze on benefits, were among the biggest drivers of financial damage for single mothers. Launched by former chancellor George Osborne as a crackdown on those he claimed were “living a life” on public assistance, the benefits cap restricts total benefits, including for housing costs, to £20,000 a year for families outside London and £23,000 in the capital, regardless of the family’s needs. Official figures published last month showed 67% of capped households, or about 80,000, are single-parent families. Alison Garnham, the chief executive of the Child Poverty Action Group, said: “This alarming research is a wake-up call showing the need for additional support for families with children in response to the cost of living crisis. “It is no surprise to see child poverty rates rising fast for lone-parent families after the harsh effects of years of benefit cuts and freezes, and with no shock absorbers left to deal with inescapable soaring living costs.” A spokesperson for the government said the living wage had been increased significantly to £9.50 an hour, it had expanded access to free school meals and that universal credit reimburses claimants for up to 85% of childcare costs. “We recognise people are struggling with rising prices which is why we are protecting the eight million most vulnerable families with at least £1,200 of direct payments this year.”