"And I've got to tell you, I hear it repeatedly. I have employers stopping me in the street and saying, 'I'd take more of your people if they would only pass the drug test.'
"And it's in the forestry industry, it's in construction - we're just seeing over 40 per cent of jobs that come in require people to be able to pass a clean drug test."
Ms Bennett said she did not know if there was an increase in drug taking.
"I think what has changed, if you like, in the last 10 years, is that employers have started drug testing. So that wasn't around 15 years ago," she said.
"Employers have an expectation now around health and safety, and as a consequence we have a portion of society who can't actually reach that obligation."
Sanctions will also extend to beneficiaries who miss court appearances or are subject to an arrest warrant.
The latest welfare reforms also change the benefit categories.
All but the seriously disabled and long-term sickness beneficiaries will fall into one category, under which they will be required to look for work as soon as they are able to and must reapply for the benefit on a regular basis.
The reforms will also require parents to get health checks and early childhood education for their children or risk benefit cuts.