Labour is to make a fresh attempt to overturn the cuts to tax credits introduced in the summer budget by tabling changes to the welfare bill due to be debated next week.

Owen Smith, the shadow work and pensions secretary, said the Labour amendment would give Tory MPs one last chance to reverse tax credit cuts for 3 million families before they face a storm of protest in their constituencies about the changes when voters’ pay packets are hit next year.

Speaking at Conservative conference, David Cameron said “we’ve had the vote in parliament on tax credits” and claimed once again that the reduction would be offset by the introduction of the “national living wage” next April.

Smith said he was proposing a fresh amendment to the bill, which will be debated in committee next week.

He was speaking after new evidence provided by the Resolution Foundation thinktank showed that as many as 200,000 working families fall below the government’s old child poverty line as a result of the budget changes.

In advance of that vote, Smith has also written to the chancellor, George Osborne, demanding that the Treasury publishes a full assessment of the cumulative impact of the tax credit and benefit reforms.

Andrew Tyrie, the Treasury select committee chairman, wrote to Osborne in August asking for a full distributional impact of the budget, but no reply has been published on the committee’s website.

The committee was critical of the government’s refusal to provide these details in an evidence session with Osborne.

Smith said: “The prime minster tried to tell us that the tax credits cut was done and dusted and that parliament had no further opportunity to debate its impact on working households. However, in light of emerging evidence from a range of experts, including the Resolution Foundation – and criticism from his own top team – that these cuts will hammer the very hardworking people he claims to speak for, I am offering the prime minister another chance to let his MPs vote with Labour and reverse the cuts.



“It’s now quite clear that the scale of the damage these cuts will cause is far greater than the government has let on, and is in no way offset by the 70p increase in the minimum wage. That’s why, ahead of the vote, I have also written to George Osborne demanding that MPs be given full possession of the facts and that the Treasury publishes a full and frank assessment of the impact these reforms will have year on year, worker by worker.”

