The Labour Party says the Government will have to divert huge amounts of money from existing services to pay for Whanau Ora.
Funding details for the scheme are yet to be announced, but the Government has said it will be paid for out of existing budgets for health, social development and Maori Affairs.
Labour says there is no evidence it will be an improvement on existing programmes.
It says agencies such as the police, health and Child, Youth and Family are not awash with spare cash.
Health spokesperson Ruth Dyson says there are still a lot of unanswered questions about Whanau Ora.
She told Morning Report she wants to know what social and health services will be cut to pay for it.
She says other questions such as how Whanau Ora will be delivered also need to be answered.
Finance Minister Bill English says Whanau Ora may receive a small amount of start-up funding, but over-all, it will be fiscally neutral.
He has reiterated that Whanau Ora will be available to all New Zealanders, not just Maori.
Less bureaucracy - Turia
Whanau Ora Minister Tariana Turia says the benefits are unlikely to be immediate.
She says it will allow Maori and other providers to consolidate support for families which are currently split across a range of contracts.
Mrs Turia told Waatea News that essentially it will mean there will be less bureaucracy over time.
She said the Government expects its agencies to look at how they will integrate contracts in the health and social services sector.
Mrs Turia told Morning Report that she has great confidence in the policy as it is an outcomes-based approach assured to get results.
Whanau Ora will streamline red tape
The Waipareira Trust in Auckland says the Whanau Ora policy will offer a way to streamline regulation and provide value for money.
The trust has already invested in integrated family centres but says its health, welfare and education work is complicated by 78 contracts. It says that means about 10 audits per year.
Chief executive John Tamihere told Nine to Noon that community groups can react faster to trends in their communities and ensure families that are genuinely in need are helped.