Labour leader Chris Hipkins.

The opposition says the government's social housing shake-up is "cruel" and will lead to more evictions of public housing tenants who will be "driven deeper into poverty".

But the finance minister has defended the move, saying it's about fixing an unfairness where those in social housing have "won the lotto" compared to others doing it tough who do not have access.

The government has announced a major shake-up of social housing beginning in this year's Budget - which will boost weekly support for 110,000 families by almost $15 but leave another 80,000 families worse off by $30 a week.

The change will be paired with more stringent criteria for getting a social house - and possibly new tenancy duration limits and regular check-ins.