LOS ANGELES — City Council leaders in the nation’s second-largest city voted Tuesday in favor of hiking the minimum wage to $15 an hour by July 2020.

The council approved the measure in a 14-1 preliminary vote. The city attorney’s office will draft an ordinance on the increase and submit it to the council for a final vote.

The vote followed months of debate over how quickly the current $9 an hour minimum should rise. It is already slated to go to $10 in January. Under the proposal approved today, Los Angeles would increase its minimum hourly wage every year so that it hits $15 by July 2020.

If the final plan is approved, Los Angeles will join Seattle, San Francisco and a number of other West Coast cities in raising the minimum wage well above the federal floor of $7.25 an hour.

As part of a national campaign to reduce poverty, there has been an aggressive push nationally, led by labor and community groups such as Raise the Wage Coalition, to increase minimum wages for American workers in industries such as big box retailers and fast-food restaurants.

“It’s very significant,” said Paul Sonn, the general counsel at the National Employment Law Project. “Los Angeles represents the $15 minimum wage going mainstream.”

Last week Facebook required its vendors and contractors in the U.S. who do a “substantial amount of work” with the social media giant to pay their workers at least $15 an hour.

The federal minimum wage has remained at $7.25 an hour for five years. Twenty-nine states have higher minimum rates. President Barack Obama has endorsed raising it to $12 an hour.

“There’s been a dramatic change over the past two years at every level,” Sonn said. “Activists and lawmakers are pushing for much higher minimum wages.”

There are other proposals to hike wage minimums in New York City and the District of Columbia as well as Oregon and Missouri. Sonn said more states and cities are realizing that paying workers a higher wage makes good business sense.

The Los Angeles proposal would raise the minimum wage for most businesses to $10.50 an hour by July 2016, $12 by July 2017, $13.25 by 2018, $14.25 by 2019 and $15 by 2020.

Advocates, including L.A. Mayor Eric Garcetti, wanted a faster boost in the city’s wages, but business groups voiced concern that it was an economic threat to companies.

Lawmakers have struggled with how the new rules should apply to small businesses and workers who earn additional wages from tips. Small businesses and nonprofit organizations have an additional year to comply with the wage hikes.

The council will consider separately mandating paid time off for workers, pending further study.

“Pay increases are a smart strategy,” Sonn said. “It’s something we have not seen before.”

With wire services