Several public funds that hold shares in Facebook Inc on Wednesday backed a proposal to remove Chief Executive Officer Mark Zuckerberg as chairman, saying the social media giant mishandled several high-profile scandals.

State treasurers from Illinois, Rhode Island and Pennsylvania, and New York City Comptroller Scott Stringer, co-filed the proposal. They joined hedge fund Trillium Asset Management, which bought it to the table in June.

The proposal, set to be voted on at the company's annual shareholder meeting in May 2019, is asking Facebook's board to make the role of board chair an independent position.

Facebook did not immediately respond to a request for comment.

"Facebook plays an outsized role in our society and our economy. They have a social and financial responsibility to be transparent – that's why we're demanding independence and accountability in the company's boardroom," Stringer said.

The proposal said lack of independent board chair and oversight has contributed to Facebook "mishandling" a number of severe controversies, including Russian meddling in U.S. elections and the Cambridge Analytica data leak.

Zuckerberg has about 60 percent voting power, according to a filing in April. Previous efforts to remove Zuckerberg as chairman have failed.

The New York City Pension Funds owned about 4.5 million Facebook shares as of July 31.

The Pennsylvania Treasury holds 38,737 shares of the company, according to a spokeswoman. Trillium holds 53,000 shares.

Shares held by the Treasurers of Illinois and Rhode Island were not immediately available.