Casual labourers are quitting $15-an-hour jobs claiming they can make almost the same on the dole.

Alpha Recruitment managing director Colin Mathieson said three staff had walked out in recent weeks, saying they would receive just $20 less each week on benefits.

The three, fathers from south Auckland, said they would receive family tax credits and accommodation supplements on top of their benefits.

Tradestaff owner Kevin Eder said travel costs involved with getting to and from work could also be factored in.

Work and Income calculations didn't support the fathers' claims.

The agency said a three-child family living in Mangere with two parents on benefits would receive $750 a week. If one of the parents worked 30 hours in a casual $15-an-hour job, they would receive $826, and $923 for working 40 hours.

Employees who voluntarily left a job would be stood down from benefits for 13 weeks.