The coalition government has confirmed this year's Budget will include a $24 million spend over four years for the I Am Hope initiative Gumboot Friday, providing counselling to young people.
But the opposition is calling for more transparency around mental health services procurement.
Mental health campaigner Mike King and I Am Hope chair Naomi Ballantyne joined Deputy Prime Minister Winston Peters and Mental Health Minister Matt Doocey to announce the move at Parliament on Wednesday morning.
Peters said the money would enable the charity to provide access to free mental health counselling services for more than 15,000 young New Zealanders per year, more than doubling its reach.
A commitment to $6m in extra funding for the charity was included in the NZ First-National coalition agreement.
National also promised during the election campaign last year to set up a $20m Mental Health Innovation Fund which would help providers and other NGOs.
Doocey said prevention and early intervention were a critical part of dealing with mental health, and Gumboot Friday played a vital role in enabling young people with mild to moderate mental health needs access to counselling services earlier.
He said research had found every $1 invested with I Am Hope resulted in a social return to New Zealand worth $5.70.
He believed the "mental health debate is largely driven by young people in New Zealand", suggesting they were articulate about mental health in a way older generations had not been.
King said every cent would be reported and accounted for.
"Every single cent, $24 million, is going directly to counsellors. Mike King is not putting a single cent in his pocket, I Am Hope Foundation is not putting a single cent in its pocket, this is about the kids," he said.
"They say it only takes 16 years to be an overnight sensation ... I've been working with I Am Hope since 2009. In all that time we've not been funded one cent, everything we have built up we have built up with the backing of ordinary New Zealanders who have been funding this operation."
He thanked the coalition government for "believing in what we do", and pointed as well to Deputy General of Mental Health Robin Shearer and her team.
The funding would also allow I Am Hope to bring in another 300 counsellors, he said.
He said the charity was data-driven, and their figures showed the interaction between parents was one of the main concerns for young people.
Doocey also pointed to further work planned in mental health crisis response.
"When you call 111 with a physical health crisis, you get a health response. When you call 111 with a mental health crisis in New Zealand at the moment you get a criminal justice response.
"I want to thank the police for turning up, they do a good job but clearly ... we need a better mental health response and that will be a key piece of work going forward."
Labour's Mental Health spokesperson Ingrid Leary said Doocey needed to be fully transparent about the procurement of mental health services.
"Any help for youth mental health services is welcome news, however the blatant leveraging of the good name of a charity with no transparent procurement process by a Minister with no recognised clinical expertise is questionable practice," she said.
"In his desperation to distract from the Suicide Prevention Office debacle, the Minister has sacrificed due process for political expedience, despite warnings in Treasury documents."
She said no one questioned that charities like Gumboot Friday had a role to play, but funding it in this was was "just plain wrong".
"Taxpayers have a right to know that their contribution to youth mental health has been procured fairly and transparently, involves no conflicts of interest, safeguards recognised clinical standards of care, and provides value for money."
'Not anywhere near far enough'
Dr Hiran Thabrew from the Australia New Zealand College of Psychiatrists, said the cash for the Gumboot Friday charity was "not anywhere near far enough to address the mental health crisis in the country".
"We know that counselling services are important but they're not a silver bullet," he said.
"As we've said many times before, we have a dire shortage of specialist professional mental health professionals, hospital beds and crisis-driven emergency care that does need substantial investment, particularly taking into account the needs of the estimated 280,000 New Zealanders with moderate to severe mental illness."
Prior to the election, the College had calculated that clinical services needed another $25m over three years just to keep up with population growth.
"We're not denying there is a need for services for those with milder issues," Thabrew said.
"But given there was significant investment by the last government into primary care mental health services and there's been no investment in specialist mental health services for over a decade, this does nothing to help those who are more unwell."
Changing Minds' kaiwhaihua, Jodie Bennett, said the organisation welcomed "any type of investment into anything in the mental health and addiction setting".
"We're hopeful for our rangatahi that this has some sort of impact for them.
"But we would like to see the same speed applied to investment into other areas of mental health and addiction, including into our sector."
Investment into early intervention services was "critical", she said.