Controversial welfare bill passed by 308 votes to 124
The Work and Pensions Secretary claimed some Opposition politicians had failed to learn anything from “mistakes” made when last in government over proposed reforms to tax credits.
He was speaking before the vote which saw the bill was passed by 308 votes to 124.
Acting Labour leader Harriet Harman was expected to face a backbench rebellion over her refusal to oppose the Welfare Reform and Work Bill outright.
The Labour front bench has accepted the need for welfare changes but disagrees with some of the policies and the approach adopted by ministers.
Mr Duncan Smith outlined the plans, which include limiting tax credits to two children and a further reduction in the benefit cap, as he moved the Bill’s second reading.
On tax credits, he said: “In 1980, working age welfare accounted for 8% of all public spending but by 2010 it had risen to nearly 13%. That’s more than £2 billion, almost £8,000 for every household.
“Nine in 10 families who had children were eligible when we came into Government for tax credits.
“And so from last week it’s clear many of the other side still, I don’t believe, have actually learnt anything from some of the mistakes made during the 13 years of the Labour government.
“They haven’t weaned themselves off the addiction to pay debt and more debt off somebody else’s money, and they are still not credible when it comes to managing the public finances.
“As a result of our reforms, five in 10 families with children will be eligible for tax credits, bringing a greater balance to the welfare budget.
“However, it’s also clear in the Bill we have been careful to ensure that the changes are fair.
“We are protecting the most vulnerable in society, including the elderly and disabled, and where possible we’re only introducing changes for new claimants only so those people who have planned on the basis of what is currently available are not affected.”
Democratic Unionist Ian Paisley (North Antrim) warned lowering the benefit cap to different levels for London and elsewhere in the country - £23,000 and £20,000 respectively - set an “unwanted precedent” for other benefits.
London has previously been “disproportionately” affected, Mr Duncan Smith said.
The Cabinet minister added the planned reforms would affect 16,000 people living in London and 77,000 from outside the capital.
Mr Duncan Smith also told MPs: “The reality of this is none of this is in any way absolutely perfect but we believe this resets the balance better than just leaving a single figure at a lower level that makes London suffer more than the rest.”