The Green Party has accused Associate Social Development Minister Jo Goodhew of being out of touch with the pressures beneficiaries are under.
Mrs Goodhew has blamed a sharp rise in assaults on Work and Income staff on copycats of last September's fatal shooting in Ashburton.
In the past year, 46 staff were seriously assaulted and more than 400 beneficiaries trespassed from the agency's offices.
Greens social development spokesperson Jan Logie said the incidents were not related to what happened in Ashburton.
"If you talk to staff as well as beneficiaries, everyone's talking about how the system workloads have gone up, sanctions have increased...
"People's ability to put food on the table is at stake and sometimes people act unpredictably when they're under that kind of stress."
She said the Government should do a comprehensive review of the dealings at Work and Income offices.