A group called Portlanders for a Living Wage officially kicked off its campaign Monday to increase the minimum wage in Maine’s largest city to $15 an hour.

Supporters made their first appeal to city voters during a news conference on the sidewalk in front of the McDonald’s restaurant on St. John Street. McDonald’s is one of several national franchises that are targeted by the proposal drafted by the Portland Green Independent Committee.

“We chose to hold this conference here today because the service industry – particularly the fast-food industry – is symbolic and emblematic and symptomatic of the unfairness of the current wage market,” said Mako Bates, a member of the group’s steering committee. “We need fair wages for Portland workers. That means a living wage.”

Question 1 on the Portland city ballot Nov. 3 will ask voters whether they support “An Ordinance Toward a Living Wage,” which would raise the minimum wage for all workers, including tipped workers. The ordinance would be phased in, with businesses that have 500 employees or more having to pay their employees $15 an hour starting in 2017 and everyone else reaching that rate by 2019. Starting in 2020, annual raises in the minimum wage would be tied to inflation. Tipped workers would earn a base wage of $3.75 less than the minimum, although employers would have to make up the difference if customer tips don’t push them over the minimum wage.

George Lydick, who owns the McDonald’s on St. John Street, as well as a McDonald’s in Falmouth, said the proposal would force him to raise menu prices and possibly cut back on staff in Portland, especially among younger, less experienced workers. Lydick said he employs about 50 people in Portland and another 35 in Falmouth.

Instead, Lydick said, residents should allow the minimum wage increase enacted by the City Council this month to take effect.

That increase was proposed by Mayor Michael Brennan and would increase the minimum wage to $10.10 an hour on Jan. 1 and $10.68 an hour the next year, with future increases tied to inflation. Brennan’s proposal will not increase the base wage for tipped workers, who would still earn half of the state’s minimum wage of $7.50 – not including tips. If those workers do not make the new minimum after tips are counted, then the employer must make up the difference.

“It allows the workers to make more money and businesses to remain profitable,” said Lydick, who said his employees currently start at $9 or $10 an hour. “It will be up to Portland voters to decide whether they want to go along with the mayor’s more measured approach.”

There is a national movement to raise the minimum wage to $15 an hour. Seattle has already adopted that wage and New York City recently enacted it for fast-food workers.

Tom MacMillan, chairman of the Portland Greens and a candidate for mayor, said a $15-an-hour minimum wage is warranted in Portland because of its cost of living and skyrocketing rents.

“The cost of living is tremendous in Portland,” MacMillan said. “Poverty is the No. 1 problem we face today. Voting yes means a better life for Portland workers. It means a more humane city where no one is left behind just because they happen to work for a business that pays poverty wages. It means dignity for working people.”

According to a news release, groups endorsing Question 1 include the Cumberland County Food Security Initiative, Southern Maine Labor Council, Maine State Nurses Association, Maine AFL-CIO, Restaurant Opportunity-United, Socialist Alternative Maine and Food & Water Watch Maine.

Meanwhile, a group composed of small businesses and nonprofits that is called “Too Far, Too Fast” is actively opposing the $15-an-hour minimum and issued a response Monday.

“Pushing the market immediately to (a) $15 minimum wage makes Portland an outlier, and threatens small businesses’ viability to pay their workers and nonprofits to fulfill their mission of helping the neediest of Portland,” said Chris Hall, the CEO of the Portland Community Chamber of Commerce, which is leading the coalition. “Portland shouldn’t become an outlier. We will get to $15, but Question 1 on Portland’s ballot goes too far, too fast.”

The opposition group noted that there could be a statewide referendum in 2016 to increase the state’s minimum wage to $12 an hour over the next few years. The group noted that the mayor’s minimum wage plan already puts Portland’s wage at the seventh highest in the country.