|The Work and Pensions Secretary Iain Duncan Smith has said that planned changes to disability benefits will go ahead, insisting that the reform is needed.|
The new reforms could see half a million people losing the Disability Living Allowance over the next four years.
But Mr Duncan Smith told the Daily Telegraph that the number of people claiming it had risen by 30% in recent years, with many people "allowed to fester".
Mr Duncan Smith said: "It's been rising well ahead of any other gauge you might make about illness, sickness, disability or, for that matter, general trends in society.
"A lot of that is down to the way the benefit was structured so that it was very loosely defined."
Labour said he was approaching reform with "contempt and carelessness".
Currently, people with a physical or mental disability can claim Disability Living Allowance. This has to be severe enough that they need help caring for themselves or have difficulty walking.
It can be claimed irrespective of employment status, and is not usually affected by savings or income.
Under the changes, two million claimants would be reassessed in the next four years, with only those considered to be in need of support able to qualify.
The allowance is currently claimed by more than three million people - but it is due to be replaced with a "personal independence payment", which ministers say will focus on those most in need.
Mr Duncan Smith said the current system had been exploited and abused because of political fear about reforming a benefit for the disabled.