PROVIDENCE, R.I. — Rhode Island public workers and retirees pushed back today against a major public pension overhaul proposal, urging lawmakers to slow down their deliberations to ensure any changes are fair.

This is another showdown between public worker unions and state governments that have occurred this year.

Philip Keefe, president of the state’s second largest public sector union, told lawmakers reviewing the proposal that it treats lower-paid workers as “serfs.” Keefe leads the Rhode Island Alliance of Social Service Employees.

He said, “Put some breaks on this. I don’t think we need to try to fix a 20-year problem in two weeks.”

The legislation from Gov. Lincoln Chafee, an independent, and Treasurer Gina Raimondo, a Democrat, calls for a new system that combines 401(k)-style accounts with traditional pensions. The plan would halt cost-of-living pension increases for most retirees for a projected 19 years and raise retirement ages.

Hundreds of public workers and retirees gathered at the Statehouse to watch as lawmakers continue hearings on the proposal. They planned to hold a protest later today, and a business-backed group called EngageRI planned its own rally to support the proposed changes.

Chafee and Raimondo say the legislation will save billions and protect future retirement benefits. Public unions call the plan unfair and vow to sue if lawmakers adopt it.

The state’s pension system faces a $7 billion unfunded liability.