Palo Alto council members will have to take a public vote before every closed-door meeting under a new policy that the City Council adopted on Tuesday night.

The policy, which the council adopted unanimously, requires members to vote immediately before convening behind closed doors to talk about things like labor negotiations, litigation, real estate negotiations and personnel matters. It came at the urging of Councilman Greg Scharff and Vice Mayor Greg Schmid, both of whom also lobbied for the policy last October in the council's Policy and Services Committee.

Last year, the proposal faltered in the committee by a 2-2 vote, with Larry Klein and Gail Price voting against it. With Klein and Price no longer on the council, the change advanced with little debate and no dissent.

"I think this is an easy change," Scharff said. "What this simply does is allow us to have this contemplative moment where we all sit together and decide, 'Do we really want to go into a closed session?'"

The decision to change the policy was prompted by several instances over the last two years in which the council faced heavy community criticism for opting to go behind closed doors to discuss subjects that many felt should have been publicly vetted first. In April, residents protested the decision by the council to schedule a closed session to discuss the future of Cubberley Community Center, prompting the council to reschedule the closed session until after the May public hearing on the topic.

Council members also found themselves on the defensive after residents learned that the council had met behind closed doors in 2012 to discuss a proposal from billionaire developer John Arrillaga to buy a 7.7-acre parcel of land near Foothills Park. Though the sale did not go through (the land was ultimately dedicated as parkland), residents and the Santa Clara County Grand Jury pointed to the closed-session discussion as an example of the council acting in a manner that is less than transparent.

Schmid said that of the dozens of closed sessions that the council has held since he was elected in 2007, only four were controversial (Cubberley, the Foothills parcel, interviews for a new city manager and labor negotiations involving the non-unionized group of managers and professionals).

"Ninety-eight percent of the closed sessions we go into would be pro forma," Schmid said. "It's clear to me and clear to the public."

But if there is a question about whether a closed session is necessary, council members will now have a chance to vote on it.

Councilman Pat Burt agreed that the change is worthwhile.

"I think it's a good proposal," Burt said. "It's going to cause us to be thoughtful and affirmative every time we go into a closed session. I expect it will mean fewer closed sessions. I expect it will have an impact, not a radical one, (but) one that will be helpful and constructive."

With the change, Palo Alto becomes only the second city in the region to require a public vote before closed sessions. Currently, only San Francisco requires its elected leaders to do that, City Manager James Keene said. He called the policy change "another advance in our city's focus on open government."

"This would be an improvement in the current practice, in our view," Keene said.