Jobseekers face temporary benefits bans if they refuse to take some forms of zero-hours contracts under the coalition Government's welfare reforms.
Claimants risk losing payments for more than three months if they fail to accept certain positions on such terms as part of the n ew universal credit system.
Employment minister Esther McVey outlined the change in a letter to Labour MP Sheila Gilmore in an exchange about benefits sanctions, according to the Guardian.
Jobcentre "coaches" will be able to "mandate to zero-hours contracts" if they consider the role is suitable for a claimant, it added.
Ms Gilmore told the Guardian: "While I don't object to the principle of either universal credit or zero-hours contracts, I am concerned about this policy change.
"I also fear that if people are required to take jobs with zero-hours contracts, they could be prevented from taking training courses or applying for other jobs that might lead to more stable and sustainable employment in the long term."
Last week unions called for action against zero-hours working after a study showed about 1.4 million jobs involve contracts that do not guarantee a minimum number of hours.
The Office for National Statistics (ONS) said most of the contracts were zero hours, under which people are not guaranteed work from one week to the next, but officials pointed out that some workers could have more than one contract.
A study among employers showed that 13% used non-guaranteed hours contracts, rising to almost half in the tourism, catering and food sectors.
More than one in five employers in health and social work reported using them, but they were relatively rare in financial, manufacturing, energy and agricultural services.
A Department for Work and Pensions spokesman said: " With Universal Credit, claimants will not be required to sign up to exclusive zero hours contracts. As now, if there's a good reason someone can't just take a particular job they won't be sanctioned.
"But it is right that people do everything they can to find work and that we support them to build up their working hours and earnings. The average zero hours contract provides workers with 25 hours of work a week - and can lead to long-term opportunities.
"Universal Credit payments will adjust automatically depending on the hours a person works to ensure that people whose hours may change are financially supported and do not face the hassle and bureaucracy of switching their benefit claims."
Shadow work and pensions secretary Rachel Reeves said: "Just last month, Employment Minister Esther McVey said that no-one at Jobcentre Plus would be forced to apply for a job offering a zero-hours contract. Now we hear that they'll receive sanctions if they don't.
"David Cameron's Government now needs to urgently clarify the circumstances in which someone will be forced to take a zero-hours job.
"The huge increase in zero-hours contracts under the Tory-led Government is another sign of their failure to tackle the cost-of-living crisis and deliver a recovery that works for everyone.
"Labour would outlaw zero-hours contracts where they exploit people, as well as improving opportunities for jobseekers by reforming the failing Work Programme.
"Labour's Compulsory Jobs Guarantee would also get the long-term unemployed into a 25 hours-a-week, paid job - work they'd have to take or lose their benefits."
Asked whether David Cameron thought it was right for jobseekers to face benefit sanctions if they turn down zero-hours contracts, the Prime Minister's official spokesman told a regular Westminster media briefing: "He does think that it is right, as part of the introduction of Universal Credit, that there should be a requirement on people to take work opportunities that are offered, such as the ones you refer to.
"Individual decisions about tailored work requirements for people who are in receipt of taxpayer-funded benefits are taken on a case-by-case basis by Jobcentre staff.
"But as a point of principle, should we be expecting people to seek employment in return for benefits and do we have a system, in the Universal Credit, that is designed to respond to changing earnings? He does think that's the right approach."
TUC general secretary Frances O'Grady said: "The Government is blaming unemployed people for losing their jobs, and imposing a regime that looks more and more like punishment rather than real help back to work.
"Forcing people into uncertain employment is not the answer to unemployment and may restrict the ability of claimants to seek secure, permanent work. We know that for many workers zero-hours contracts mean zero job security, poor pay and no way of knowing what they'll be earning from one day to the next.
"An increasing number of unemployed people are being penalised for breaking rules unintentionally and are facing life with no benefits for months as a result."