Labour has failed in its attempts to use an arcane parliamentary mechanism to force the government to release internal documents on the impact of universal credit.
MPs voted down the motion by 299 votes to 279, allowing ministers to keep the papers secret.
Labour had tabled a “humble address” seeking the release of Whitehall analysis of how the controversial welfare changes affected family incomes.
The technique has been used to force publication of government assessments on the impact of Brexit. It involves MPs asking the Queen to instruct ministers to release the documents, and is legally binding.
Labour had sought the release of “any briefing papers or analysis ... on the impact of the roll-out of universal credit on recipients’ and household income and on benefits debts” given to the work and pensions secretary, Esther McVey, since she took office in January.
Universal credit, which merges six benefits into one payment, has been widely criticised for its impact on low-income families.
Earlier this week, leaked documents suggested the national roll-out of the policy could be delayed further as the government struggles to prepare for transferring 8 million people to the new system.
Ministers have already had to make changes to the administration of payments following reports that delays were forcing people into destitution.
Ms McVey has admitted some recipients will be “worse off” under universal credit.
She also reportedly told the cabinet some people will lose up to £200 a month under the policy.
Downing Street denied this, however, insisting “no one moving on to universal credit would lose out”.
Speaking ahead of the Commons debate, shadow work and pensions secretary Margaret Greenwood said: “Universal credit has pushed many families into poverty, debt and misery. Even Esther McVey has admitted that families will be worse off.
“Despite the evidence, the government is pressing ahead with the roll-out.
“The government must come clean about its plans and make public what they know about the impact of the roll-out of universal credit on vulnerable people and families. The roll-out of universal credit must be stopped immediately.”
Responding in the Commons, Ms McVey said her department had “gone to great lengths to be open”.
She said the government had previously published a summary of the business case for universal credit, which suggested it would help 200,000 people into work. She said other organisations had also published hundreds of reports on the topic.
“We are open with our information,” she said.
“We are learning from that evidence, we are building on that evidence and we are making decisions so we can improve the system as it goes further.”
She insisted the roll-out of universal credit would continue, saying: “We will make sure we get this benefit right. You know for why? Because the genuine concerns of the people on our backbenches want to get it right.”
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