MPs have called for a full independent review of Iain Duncan Smith’s benefit-sanctions regime in the next parliament amid growing fears of their impact on vulnerable claimants.

In a hard-hitting report published today, members of the House of Commons’ work and pensions committee said there were increasing concerns civil servants were under pressure to achieve targets to apply a certain numbers of sanctions.

Dame Anne Begg, the Scots Labour MP and the committee chair, said: “Benefit sanctions are controversial because they withhold subsistence-level benefits from people who may have little or no other income.

“It is essential that policy is based on clear evidence of what works in terms of encouraging people to take up the support which is available to help them get back into work. The policy must then be applied fairly and proportionately.

“The system must also be capable of identifying and protecting vulnerable people, including those with mental health problems and learning disabilities. And it should avoid causing severe financial hardship. The system as currently applied does not always achieve this.”

Sanctions were extended under the Coalition Government’s Welfare Reform Act 2012, meaning claimants lose a minimum of four weeks’ Jobseeker’s Allowance if they breach certain rules such as being late for an appointment or not completing a required number of job applications.

More than 80,000 out-of-work Scots have had their benefits stopped for a minimum of four weeks since the new sanctions regime was introduced just over two years ago.

The most severe sanction sees Jobseeker’s Allowance withdrawn for 13 weeks when, for example, an individual leaves a job voluntarily. This rises to 26 weeks for a second “failure” and 156 weeks for a third.

A total of 81,980 people in Scotland, including parents with young children, were hit by 143,671 sanctions which saw them barred from receiving Jobseeker’s Allowance, currently £72.40 a week for those over 25.

The figures were released by the DWP last month, and covered the period from October 2012, when the new sanctions system was introduced, to September last year.

The UK Government says the regime provides an extra incentive for claimants to seek work.

But critics argue the system punishes those who have caring responsibilities or may be especially vulnerable because of literacy or health problems, forcing many to turn to food banks to feed themselves and their families.

Begg said there was currently no evidence on whether the application of sanctions , or the deterrent threat, made it more or less likely that a claimant would engage with employment support or gain work. She added: “This is an area of policy which must be based on robust evidence. The department needs to demonstrate that the application of the new sanctions regime is not intended to be purely punitive.”

The MPs also drew attention to the concern many benefit claimants have taken their own lives and said the DWP should investigate all deaths “where suicide is associated with DWP activity”.

Their report said that since February 2012, DWP has carried out 49 peer reviews following death of benefit claimants, though it was unable to confirm in how many cases the claimant was subject to a benefit sanction.

A DWP spokeswoman refused to say how many deaths were in Scotland on the basis that the information could breach claimant confidentiality and privacy.

Begg added: “We have asked DWP to confirm the number of internal peer reviews in which the claimant was subject to a benefit sanction at the time of death, and the result of these reviews in terms of changes to DWP policy.

“It is important that all agencies involved in the provision of public services are scrutinised to ensure that lessons are learned after members of the public are let down by the system, particularly where the failures of a public body may have contributed to a death. We believe that a new independent body should be established to fulfil this role.”

The work and pensions committee previously urged ministers to hold an inquiry into sanctions in January last year but the call was rejected by the Government.

Last night MPs said the move was now particularly pressing in light of new evidence which raises concerns about the approach being adopted in a number of individual Jobcentres and concerns about whether targets for sanctions exist.

SNP work and pensions spokesperson Dr Eilidh Whiteford MP said: “Unfair sanctioning imposed by the DWP is hurting families across Scotland."