The government is not doing enough to help disabled people into work, the national spending watchdog has said.
Half of people of working age with disabilities are not in work
The National Audit Office found 5% of the 2.6 million people on incapacity benefit were supported by back-to-work schemes in 2003-4.
More needed to be done to increase the numbers assisted into work and to aid job retention, its report said.
Employment minister Margaret Hodge said schemes were being reviewed as it was recognised more needed to be done.
Benefit shake-up plans were this week outlined by Work and Pensions Secretary David Blunkett, who said getting a job could help people overcome stress and depression.
He wants to get as many as one million of the current 2.7 million on incapacity benefits into work.
However, only 50% of the 6.7 million disabled people of working age in Britain are in work - compared with 75% of the working age population as a whole.
This leaves 3.3 million people with disabilities not in work.
The government's spending watchdog said although not all people with disabilities would be able to find work, many would see "significant positive impacts" if they did.
David Blunkett has said the current system of benefits is 'crackers'
The NAO praised the range of schemes available but said: "The programmes only support a small number of people who could potentially benefit.
"In 2003-2004 there were more than 2.6 million people of working age on incapacity benefits.
"In comparison, around 125,000 were involved in one or more of the department's (for work and pensions) programmes."
Not only people with physical and sensory impairments qualify for incapacity benefit.
It also takes in those with mild to moderate health conditions and those with minor mental health illnesses.
'More to do'
Mrs Hodge said the NAO report rightly recognised much of the progress the department had made with 280,000 disabled people being helped into work since 1997.
But she said the department recognised there was more to do which was why employment programmes were being reviewed.
"We are building on this success with proposals in our forthcoming Green Paper which will help more disabled people into work," she said.
Ian Charlesworth, managing director of the Shaw Trust charity which provides employment services for disabled people, said: "This report says what we've been saying for a very long time.
"There are hundreds of thousands of people we could be helping every year, but can't because of funding restrictions or bureaucratic tangles.
"Getting this right will make a massive difference, not just to disabled people but also to the economy through reduced benefit bills and a larger workforce."
Benefit payments to people with disabilities or health problems totalled £12bn in 2003-04.