Mayor Bill de Blasio wants state lawmakers to expand tenant protections for the city's 1 million rent-regulated apartments.

He unveiled several proposals Tuesday. They include eliminating a rule that lets landlords automatically increase rent by 20 percent each time a tenant moves out and setting new restrictions on rent surcharges for apartment or building improvements.

The existing rent regulations expire June 15.

Affordable housing is one of de Blasio's centerpiece issues. He says strengthening the rent rules is "a vital priority."

Tenant advocates are praising the mayor's stand. But the Rent Stabilization Association, a landlords' group, says the current regulations have worked well when it comes to money for building improvements.

The Daily News first reported the proposals.