Benefits sanctions are trapping people in jobs where they are unable to work enough hours to make ends meet, MSPs have been told.
Changes to the welfare system introduced by the UK Government mean that those who are underemployed may be better off not working at all, according to benefits advice services.
Holyrood's Economy Committee was told that those working less than 24 hours each week were being hit by cuts to benefits such as Working Tax Credit and Child Benefit, pushing them further into poverty.
Meanwhile, benefits sanctions - which were tightened up from October last year - can be imposed on people who leave their job, or on those who turn down a job offer, even if they are working too few hours to earn a living. The sanctions mean they do not receive any money for a period of time.
The committee is investigating the problem of people working fewer hours than they want to and being unable to fully use their skills in their job. Lauren Wood, social policy officer at Citizens Advice Scotland, said people across the country "struggle to make ends meet on the hours they have" and "struggle to increase their hours".
She said: "On that borderline it can be a real disincentive to work. If people are constantly having those barriers put in place, and on paper they would have about the same income on jobseeker's allowance as they would in their 16 hour a week job...there is a real disincentive to work."
Asked if in some cases people would be better off not working, Norma Philpott, chief executive of Citizens Advice and Rights, Fife, told the committee: "In theory they might well be. I think that is the problem that faces a lot of people - that decision of whether they go into employment or not."
Ms Wood said one client had been sanctioned for leaving a job with a four hour per week contract while another had benefits withdrawn for turning down employment because it involved a 30-mile round trip commute, yet no public transport was available and he did not have a car.
She said advice services were seeing cases such as these on a daily basis while the length of sanctions imposed on people are getting longer, and can now extend for up to six months.
She added: "We see more and more very, very small job contracts where people are taken on with promises there will be more hours. You can be sanctioned for leaving any job, and in a lot of cases the sanctions seem very automatic, and they don't seem considered to people's actual lives. The worse sanctions get, then the more people are trapped. It is a challenge that faces a lot of people."