BERKELEY -- City plans to raise the minimum wage, plagued for months with fits and starts, cleared a major hurdle Tuesday, when the City Council unanimously passed the first reading of an ordinance that would bring the wage to $12.53 an hour by 2016.

Earlier iterations of the measure called for an increase of as much $15.25 by 2020 and as little as $10.75 by 2016.

If the council passes the ordinance on its final reading, June 24, minimum wage earners working in Berkeley will earn $10 per hour beginning Oct. 1, $11 by Oct. 1 2015, and $12.53 beginning Oct. 1 2016.

While minimum wage hike supporters applauded the council action, they said after the vote that they fear opponents, apparently absent from the meeting, would pressure the council to scuttle the measure on its second vote.

"I was surprised tonight that (those) circulating a petition in opposition to an increase in a minimum wage had nobody here to oppose this," said Sam Frankel, chairman of the city Labor Commission. "I don't know if that means they're coming (to the council meeting) in mass on the 24th of June."

The website of the Berkeley Small Business Alliance, a new organization that does not identify its members, urges people to sign a petition calling on the mayor and council to "postpone (the) vote to raise the minimum wage in Berkeley until a thorough Minimum Wage Impact Study is completed."

The BSBA did not return an email for comment.

In a June 10 letter to the council, the organization says it is made up of restaurant owners already active on the minimum wage question, "plus a new group of retailers, who have just in recent weeks, been made aware of this issue."

The letter argues that proposed wage hikes are too rapid.

"Many small businesses will not have time to adjust and are already planning their exit strategies," it states. "Some who cannot raise prices will be forced to close while others will close their locations in Berkeley just to open through the tunnel in cities like Lafayette or Walnut Creek."

Berkeley's minimum wage ordinance has a one-year exemption for nonprofit businesses, and excludes government and nonprofit job training programs serving participants up to age 25.

The measure is silent on questions of health benefits, sick days, tips and cost of living increases. On July 1, the council is scheduled to consider a proposal to create a committee of nine business, labor and City Council representatives to address issues not included in the ordinance.

Meanwhile, a community-labor coalition, led by Service Employees International Union 1021, is pursuing a parallel proposal, planning an initiative for the November 2016 ballot that would bring the city's minimum wage to $15 in 2017.

Across the bay, San Francisco supervisors voted unanimously this week to place a measure on the November ballot to hike its minimum wage from $10.74 to $12.25 per hour by May 1, 2015, increasing to $15 an hour by July 2018, after which the minimum wage would rise with the cost of living.

A November ballot measure in Oakland proposes a $12.25 minimum wage by March 1, 2015, with subsequent cost of living increases. The Richmond City Council voted to phase in a minimum wage that would be at $13 by 2018, then increase with the Consumer Price Index.

At the state level, the minimum wage goes to $9 per hour on July 1 and $10 per hour on Jan. 1 2016. However, the State Senate recently voted to increase the minimum wage to $11 an hour in 2015, $12 an hour in 2016 and $13 an hour in 2017, after which it would increase with the CPI. The bill now goes to the Assembly.

In Berkeley, minimum wage raise supporters aren't ready to celebrate.

"I wonder what's going to happen at the next meeting and who's going to turn up protesting," Ned Perlstein, retired Laney College economics professor, said after the meeting. "The longer they stall it, the more wages are lost to the workers."