Analysis by Resolution Foundation shows Jeremy Corbyn’s party would go ahead with most of George Osborne’s planned benefits reductions

At least £7bn of George Osborne’s plan to slash welfare will go ahead after the election even if Labour wins power, an analysis of the party manifestos has revealed.

Three-quarters of the huge package of benefit cuts announced by the former chancellor in 2015 are yet to be implemented, including a major reduction in support given to the low-paid, and limiting payments to families with more than two children.

The Conservative manifesto suggested that the party would plough ahead with the cuts, should it win a majority. However, despite opposition to the cuts within Labour, the party’s manifesto only pledges to reverse £2bn of the £9bn cuts to come as part of a review, according to an analysis by the Resolution Foundation thinktank.

It comes despite the fact that Jeremy Corbyn was among 48 Labour MPs to rebel against the party whip in 2015 to oppose the cuts. Corbyn also criticised the decision by the party’s frontbench to abstain during his first leadership campaign.

There are three areas in which big cuts are scheduled to be made in the next parliament. A further two-year freeze to most working age benefits, which includes Jobseeker’s Allowance, housing benefit and child benefit, is expected to save £3.6bn a year by 2021.

Reductions in the payments given to people in work through the new universal credit system are set to save £3.2bn. Meanwhile, limiting support to two children per family and reducing payments to new families will save £2bn a year. Labour’s manifesto includes a pledge to hold a “review of cuts and how best to reverse them”. However, the Resolution Foundation said that the £2bn Labour has allocated for the review would reverse less than half of the £5bn cuts to universal credit and support for children.

It would also leave the benefits freeze intact just as inflation begins to bite. The foundation said that, under Labour’s proposals, 78% of the welfare cuts would still go ahead. It also said that neither party’s pledges to increase the minimum wage would come close to offsetting the welfare losses that low-income families face.

However, Debbie Abrahams, the shadow work and pensions secretary, said Labour’s spending plans included £20bn over the next parliament to reverse Tory cuts to social security. She added that the party was committed “to ending the benefits freeze at the earliest opportunity”.

“Our plan will improve support for young people, sick and disabled people, unpaid carers, working families, bereaved families and pensioners,” she said.

Torsten Bell, the Resolution Foundation’s director and Ed Miliband’s former policy chief, lambasted both main parties for their failure to deal with the welfare cuts.

“Tackling the renewed squeeze on living standards that risks seeing incomes actually fall for low and middle income families in the years ahead, should be front and centre of the next government’s purpose,” he said.

“Instead both parties are guilty of neglecting the living standards concerns of working families by allowing George Osborne’s welfare cuts to be rolled out, either in full with the Conservatives or largely intact under Labour’s plans.

“The concerns of low and middle income families are at the heart of Theresa May’s rhetoric but this week was a missed opportunity to live up to it. Improving the living standards of working people is the reason the Labour Party exists at all – something it’s time they remembered.”

The cuts are “heavily concentrated” on low-paid working families and will reduce their incomes by around £1,200 a year, the Resolution Foundation said. In some extreme cases, families will lose up to £3,000 a year.

It comes with the Lib Dems attempting to outflank Labour on welfare by promising to reverse all of Osborne’s cuts package, including the benefits freeze.

The party said that as a result of the freeze, a family with one low-paid working parent and two children under-seven living in London would be around £787 worse off a year by 2020-21. With other welfare changes taken into account, the family is likely to be £1,630 a year worse off by 2021.

Simon Hughes, the former Lib Dem justice minister, said: “Soaring inflation and higher prices as a result of Brexit will worsen the impact of the benefits freeze for millions of families already struggling to get by.

“But after having voted to give Theresa May a blank cheque for Brexit, Labour is now is refusing to help vulnerable families cope. It is a double betrayal.”