After his failed attempt to hike income taxes on the wealthy, Mayor de Blasio is eyeing another way to squeeze money from millionaires to fund another top priority: affordable housing.

Multiple sources tell The Post that the mayor is talking to people about how to increase the so-called “mansion tax” on homes selling for $1 million or more to help offset the cost of adding 200,000 affordable-housing units.

However, boosting the mansion tax would require Albany’s approval, and sources say that could be a major hurdle for de Blasio because Gov. Cuomo smacked down his income-tax-hike idea earlier this year.

The state mansion tax already exists statewide and levies a 1 percent fee on residential property sold for at least $1 million. In the 2012-13 fiscal year, it generated a record-busting $259 million. While it covers the entire state, The tax hits hardest in Manhattan, where seven-figure prices are common even for modest-sized co-ops and condos.

Sources said an expanded mansion tax, which would be progressive based on the sale price of a property, could generate $150 million for the city.

City Hall declined to comment.