Plans to integrate scores of existing health and social services providers into just 20 Whanau Ora organisations by July face difficulties and are optimistic, according to a top social worker.

This week, the Government announced that the Maori Party's Whanau Ora plan to increase the effectiveness of primary health and social spending for Maori and other families in need would go "live" from July.

Existing Maori health and social services will be reorganised to provide an integrated service to families with multiple issues across health, education, employment or the justice system.

However, few details are known including how the scheme will function and who the first 20 Whanau Ora providers will be.

Maori Party co-leader Tariana Turia, appointed Whanau Ora Minister on Thursday, conceded there was still much uncertainty about how the scheme would look, "because it's never been done before".

But Lucy Sandford-Reed, chief executive of the Aotearoa/NZ Association of Social Workers, said the Whanau Ora Taskforce report released this week indicated the scheme had much in common with earlier "integrated funding for outcomes" initiatives.

She said service providers often had multiple government contracts, reporting requirements and objectives.

"The essence of what this seems to be about is pulling all of those contracts together, pooling the money in a single contract and then developing the Whanau Ora outcomes with that money."

Ms Sandford-Reed said her experience of negotiating multi-agency contracts was that the process took "a lot of time and a lot of trust between the organisations in the room".

John Tamihere, chief executive of Te Whanau o Waipareira Trust in Waitakere City, has raised concerns that government departments now providing some services will be reluctant to cede parts of their budgets or control.

Ms Sandford-Reed said plans to have 20 integrated Whanau Ora providers in place by July were "quite optimistic unless they can roll in quite a good and really experienced workforce to facilitate that".

Mr Tamihere, who expects his trust will be one of the Whanau Ora providers, yesterday said the scheme meant hundreds of millions of dollars worth of existing health and social services contracts would need to be reallocated. That could prove problematic, he told National Radio.

However, work appears to be well advanced in the health sector. The National Maori Primary Health Coalition has already prepared a proposal on how its members will deliver services under the Whanau Ora model.