ThriveNYC, the city’s embattled mental health initiative, must use the lion’s share of its massive $1 billion budget to actually help those who need it most — people in crisis, City Council Speaker Corey Johnson insisted Tuesday.

“I have concerns that we need to be doing more for people with serious mental illness. That’s what we need to focus on the money on,” Johnson said on Fox 5’s “Good Day” Tuesday.

Mayor Bill de Blasio and First Lady Chirlane McCray’s signature mental health plan largely focuses on preventative measures and programs for people with depression and anxiety.

Only 12 percent of the $1 billion plan goes to people in crisis, according to DJ Jaffe, director of the Mental Illness Policy Organization.

That must change, Johnson said.

“We need to be putting that money into people that people see de-compensating on the subway and on the streets of New York City, who don’t know who they are, who can’t get the help they need.

“That’s where we need to funnel that money,” Johnson said.

Jaffe and other critics have long argued that more ThriveNYC funding should go toward preventing homelessness, arrest and incarceration of mentally ill New Yorkers.