The Portland City Council voted 6-3 Monday night to create a city minimum wage of $10.10 an hour on Jan. 1, increase it a year later, and tie future minimum wages to inflation.

After a debate that lasted nearly two hours and drew pleas from advocates and opponents, the council passed a plan first put forth by Mayor Michael Brennan, who vowed to raise the minimum wage in his 2014 State of the City speech.

“There is no science for this that has something perfect, but one thing I’m confident we’re not being is too aggressive,” said City Councilor Jon Hinck, who revived the mayor’s plan after the council’s finance committee proposed smaller increases over a longer period, with no tie to inflation.

The wage will rise to $10.68 an hour in 2017, and starting in 2018 it will increase on July 1 at the same rate as the Consumer Price Index, which accounts for inflation.

A competing proposal from the council’s finance committee was $1.35 lower to start, calling for a minimum of $8.75 an hour and $9.75 by 2020 without increasing base wages for tipped workers or pegging wages to inflation.

The state minimum wage is $7.50 an hour, 25 cents more than the federal rate.

“I think it’s clear that every member of this council wants to raise the minimum wage,” said Councilor Ed Suslovic, who sought to delay the vote by two weeks. “The question is how much, and how fast.”

During the public comment period, trade groups and business owners warned of the unintended consequences of raising the wage for businesses, while advocates for the higher minimum said that without it, people would continue to suffer.

“The fact remains that by doing this you’ll be the only city in Northern New England, New England, the Northeast and north of Washington, D.C., to have its own wage,” said Greg Dugal, executive director of the Maine Innkeepers Association and president and CEO of the Maine Restaurant Association.

Dugal urged that if there were to be any increase at all, the council should embrace the finance committee’s proposal.

“Please accept the fact that the wage can be too high,” he said.

Meanwhile, others said the council should go as far as it could to help people earning low wages.

“I see people every day who are struggling to survive on far more than the minimum wage and the reality is minimum wage is paid to the most vulnerable population,” said Roberta deAraujo, an employment attorney who works with low-income people.

“I am in favor of the most liberal increase to this minimum wage you can possibly reach agreement on,” she said.

Brennan’s original proposal called for a $9.50 minimum. The finance committee later voted to pare that proposal to $8.75 an hour out of concern about the impact on businesses.

Raising the minimum wage has been a key issue for Democrats and progressive groups, both locally and nationwide.

About a dozen American cities have enacted minimum wages that are higher than their state minimum. So far, Seattle has gone the furthest, enacting a $15 per hour wage.

President Barack Obama last year signed an executive order elevating minimum wage for some federal workers to $10.10 an hour, and urged Congress to do the same.

In Maine, besides Portland’s local effort, there are two competing citizen petitions to place referendum questions regarding minimum wage increases.

Two weeks ago, the Portland Green-Independent Committee submitted enough signatures to place a question on the November ballot asking voters to hike Portland’s wage to $15 per hour.

The city council, which has the power to adopt the referendum proposal outright before it reaches voters, is widely expected to place the question on the ballot.

Meanwhile statewide, a separate ballot initiative is underway by the Maine People’s Alliance to raise the minimum to $9 in 2017, then increase it by $1 annually until it reaches $12 in 2020.

The Maine House and Senate both voted to increase the state minimum wage, but the two chambers could not agree on the amount and the phase-in period.

All the while, Gov. Paul LePage has opposed Portland’s efforts to usurp the state minimum, calling the attempt unconstitutional. He sponsored legislation to block local minimum wage laws that are higher than the state’s, but the bill failed to attract support.

Staff Writer J. Craig Anderson contributed to this report.