about 68,000 benefit ­claimants are having their welfare payments stopped unfairly each year, heightening demand for food banks, a think tank has warned.

Policy Exchange said the figure relates to people who have their benefits taken away for the first time, only to later successfully appeal against the decision - about one-third of all those sanctioned for the first time each year.

In its latest report, Smarter Sanctions, the organisation proposes the use of a benefits card for first-time offenders to ensure they still have access to funds for up to eight weeks. In exchange, tougher penalties would be imposed on people repeatedly breaking rules on job hunting.

Guy Miscampbell, the author of the report, said: "The welfare system must have a sharp set of teeth. That is why the sanctions regime is so important.

"However, it is clear there are a significant number of people who have their benefit taken away from them unfairly. Four weeks without any money is driving people to desperate measures, including a reliance on food banks.

"Issuing first-time ­offenders, who may or may not have been fairly sanctioned, with a 'yellow card' in the form of a benefits card would be a more compassionate way of trying to help people back into work. At the same time, the welfare system must also come down hard on people who are consistently failing to do all they can to find a job."