Council Speaker Corey Johnson placed the blame for the city’s snowballing homelessness crisis squarely on the shoulders of Mayor Bill de Blasio Thursday — describing his administration’s response as merely lurching from “crisis to crisis” as the 2021 mayoral wannabe put forth his own homeless housing plan.

“We’ve lurched from crisis to crisis to crisis without any long-term strategy or vision on this,” Johnson told reporters at City Hall.

Johnson’s plan calls for the city to increase the reimbursement rates for its apartment vouchers to cover market-rate rents, which would cost an estimated $236 million over five years.

The current vouchers only provide below-market rents to landlords, providing, for example, just $1,580 per month for a two-bedroom unit. Social services groups say such low rent rates keep New Yorkers stuck in shelters, which can cost up to four times as much as the market-rate rents to operate and are often a hard-sell for outreach workers trying to talk the homeless in from the streets.

“We have failed them, over and over and over again,” Johnson said. “These are people, these are individuals, these are families who only want a safe, permanent home.

“This is, without exaggeration, a humanitarian crisis,” he added.

Department of Homeless Services officials admitted late Wednesday they don’t have a readily available tally of shelter-bound New Yorkers with vouchers who can’t find apartments.

But they added that the oft-criticized city voucher program is currently providing apartments for 65,000 people who were once homeless.

Johnson’s 202-page plan also called on the city to unify its housing agencies together with its homelessness agencies under a single deputy mayor, expand eligibility for services to help New Yorkers avoid eviction and to establish new mental services outreach teams dedicated to helping the street homeless.

There was no overall price tag for the proposal.

Johnson’s remarks come as the de Blasio administration struggles to get ahead of the homelessness crisis, despite more than doubling spending in recent years.

The Department of Homeless Services’ budget is expected to exceed $2.1 billion by the end of the city’s 2020 budget.

Even with the flood of money, the number of New Yorkers in DHS care remains near all-time highs. There were 59,836 New Yorkers living in city shelters Monday, which is down slightly from 61,115 on the same day last year.

There are roughly another 13,000 who in shelters run by other city agencies and roughly 3,600 who live on city streets or the subways.

Even de Blasio has acknowledged his administration was slow to respond to the crisis during the early days of his administration and rolled out a plan in 2017 that called for opening 90 new shelters in neighborhoods across the city.

However, that effort faces intense opposition from locals and some politicians — especially from eastern Queens and the wealthy residents of “Billionaires Row,” just south of Central Park.

Administration officials say that 31 of the shelters have opened so far and another 32 are currently under design or in construction.

One-third of the promised facilities have yet to hit the drawing board.

The struggle to open the new shelters means the number of people living in hotel shelters has swelled, despite de Blasio’s promise to shut them down.

Johnson is the second elected official eyeing a move to Gracie Mansion to blast de Blasio’s response to New York’s housing and homelessness crises in as many days.

Another likely 2021 contender, city Comptroller Scott Stringer, claimed in a blistering speech Wednesday that de Blasio’s housing policies were fueling gentrification across the city — and laid out his own plan, which experts raised doubts about.

“Through unprecedented investments in legal services and housing resources, we’ve helped more than 140,000 New Yorkers secure permanent affordable homes,” claimed City Hall spokeswoman Avery Cohen. “We look forward to continuing our collaboration with the Council as we do everything we can to bring more people home.”