Prime Minister Bill English is under attack from unions over his suggestion drugs are one reason employers are turning to migrant workers instead of young Kiwi job seekers.
The Council of Trade Unions says Mr English has used "alternative facts" to overstate the issue, and official figures show the number of beneficiaries failing drug tests is low.
"As I said yesterday it was anecdotal evidence. If people are implying that somehow this doesn't happen they should go and visit some workplaces," Mr English said today.
Mr English says the Government is committed to funding treatment programmes to help young Kiwis deal with drug issues.