Independent research into the impact of the so-called bedroom tax has been ordered by the Government, Deputy Prime Minister Nick Clegg has said.
Mr Clegg said the study was needed to find out whether tenants could opt to take a smaller house or flat to avoid a deduction in their benefits.
Under the reforms, tenants with one spare bedroom have had a payment reduction of 14% and those deemed to have two or more spare have seen their benefits cut by 25%.
For special cases, councils have been handed a discretionary housing fund to help tenants pay their rent. Labour claim that because there is a shortage of smaller properties, many tenants cannot downsize and the fund is inadequate.
Deputy leader Harriet Harman said the shortage in social housing means only one in 25 households affected by the spare room subsidy can actually choose a smaller property without an extra bedroom.
Mr Clegg told the House of Commons he suspected the problem varied across the country, adding that research was under way to determine the impact of the Government policy.
He said: “Of course, I accept that there will be cases where for some households this change from one system to another creates real dilemmas which need to be addressed through the money we are making available to local authorities.
“To be honest, I have seen lots of widely different figures being cited about the impact of this policy that is why we are commissioning independent research to exactly understand the impact of this.
“I suspect it varies enormously between one part of the country and another, and one local authority and another. That is why we are trebling, as I say, the resources we are making available to local authorities.”