The shadow education secretary, Angela Rayner, is seeking to inflict a series of defeats on the government in the House of Commons next week over cuts to free school meals and childcare.

Andrea Leadsom, the leader of the Commons, is expected to announce on Thursday that the government has granted Labour a three-hour debate and a series of votes, immediately after the chancellor’s spring statement this Tuesday.

Changes to free school meals entitlement, childcare vouchers and free childcare for two-year-olds were all due to be made using statutory instruments – without a vote in parliament.

But Labour has used an obscure process called “praying against” the regulations to secure several votes, which could prove embarrassing for the government, after Hammond’s statement.

Rayner is seeking to block a series of money-saving changes – including the imposition of an earnings threshold for free school meals – as universal credit is rolled out to more households.

Currently all families in England in receipt of UC are entitled to free school meals as a transitional measure while the new benefit is extended across the country. But the government now plans to set an income threshold of £7,400.

Rayner said: “Not only are the Tories taking free school meals and childcare from hundreds of thousands of working families but they are using arcane procedures in a desperate attempt to dodge proper scrutiny from MPs.

“If they want to take away free school meals and childcare from struggling parents in low paid jobs, Tory MPs should walk through the lobbies and vote for it.”

The government insists more families will benefit after the changes than under the old, pre-UC system.

But children’s charities say the policy will create a “cliff-edge” as families’ earnings rise. The Children’s Society claims that once a family with one child passes the £7,400 threshold, they would need to earn £1,124 a year more, the equivalent of working 2.4 hours more each week at the national living wage, to make up for the loss in free school meals.

Matthew Reed, chief executive of the Children’s Society, called for all children whose families are on UC to continue to receive a free lunch. “The government has a golden opportunity to ensure that almost every child in poverty in England does not go hungry at school,” he said.

Other policies Labour will seek to challenge during the three-hour debate are the imposition of a similar means-testing threshold for two-year-olds in receipt of free childcare and the abolition of employer childcare vouchers.

Employer-backed childcare vouchers are being phased out and replaced by a new system of tax-free childcare, but Labour claims the system is poorly understood and its rollout has been botched.

The Democratic Unionist party, whose 10 MPs usually back May’s government in major votes, has in the past opposed the abolition of childcare vouchers.

With May forced to govern without a secure majority since last year’s general election, Labour have repeatedly used votes on controversial issues such as UC to embarrass the government.

A Department for Education spokesperson said the threshold would only be applied to new claimants, so children already entitled to few school meals would not lose them.

“No child who is currently receiving a free school meal will lose out as a result of this change and it is misleading to suggest otherwise. The fact is under our new criteria, we estimate that by 2022 around 50,000 more children will benefit from a free school meal compared to the previous benefits system.‎ It’s right that we make sure this support reaches children from the most disadvantaged families.”