Benefits cap row: Iain Duncan Smith accuses BBC of seeking activists to attack benefits cap Iain Duncan Smith accused the BBC of political bias today as he defended the introduction of the Government's £26,000 a year annual cap on benefit payments for each household. The Work and Pensions Secretary clashed with John Humphrys, presenter of Radio 4"s Today programme, who said the UK Statistics Authority had questioned the minister's claim that 8,000 people had already come off benefits because of the cap. It was trialled in four London boroughs before being rolled out nationwide from today. Mr Duncan Smith replied: "No. What they [the Statistics Authority] said was that you can't absolutely prove that those two things are connected. Mr Humphrys then quoted the independent authority as saying the minister's statement was "unsupported by the official statistics published by your own department." Mr Duncan Smith replied: "Yes, but by the way you can't disprove what I said either." "You can make any claim on that basis," Mr Humphrys replied Well, I am. I believe this to be right. I believe that we are already seeing people go back to work who were not going to go back to work until they were short of the cap," Mr Duncan Smith countered. He told Mr Humphrys: "What you're doing, as always in the BBC, you're seeking out lots of cases from people who are politically motivated to say this is wrong ... The fact is that people will not be earning more than average earnings sitting out of work unless they are in exempt categories. The Work and Pensions Secretary claimed that predictions that the benefit cap would lead to thousands of people becoming homeless had not materialised. "The homeless figures have hardly moved at all," he said. He also rejected claims that the ceiling would force families to move out of London. "The vast majority of the areas in London - a third of all rentable accommodation in the private sector - is available for those who are on social rents," he said. But Ruth Davison, director of the National Housing Federation, warned: "In many parts of the country, families won't be able to pay high private rents because of the cap. There will be more demand for than ever for affordable housing, particularly in Greater London where nearly half (49 per cent) of the people affected by the benefit cap live. She added: "Families could face the stark choice of cutting back on essentials or having to move away long distances from their support networks to look for cheaper places to live. Until we see a long-term affordable housebuilding programme that will drive down the price of rents for everybody, housing costs should be removed from the cap. For Labour, Liam Byrne, the shadow Work and Pensions Secretary, said: "The benefit cap is a good idea in principle but it's already fallen apart in practice. Ministers have bodged the rules so the cap won't affect Britain's 4,000 largest families and it does nothing to stop people living a life on welfare. The Government needs to go back to the drawing board, design a cap without holes and put a two year limit on the time you can spend on the dole, like Labour's compulsory jobs guarantee.