Labour MP Natascha Engel led a Westminster Hall debate on the future of work capability assessments on 27 October 2010.
The assessments were brought in in April 2010 by the previous government to assess the work capability of people on long-term claimants of incapacity benefit.
However she raised concerns that their increasing use was solely to "bring down the welfare bill" and urged the government to see "people not the benefit".
She also claimed that there were high numbers of people successfully appealing a decision on their capability to work.
Work and Pensions Minister Chris Grayling denied that work fitness tests were a money saving exercise, and said that their aim was for people to "make more of their lives".
Over 2.5m people are on incapacity benefit or employment support allowance - costing about £12.5bn a year.