Advocates pushing Minneapolis to mandate a $15 minimum wage marched into City Hall on Wednesday, waving signs, beating drums and carrying a stack of petitions with the signatures of about 20,000 people.

Organizers had been working since late February to gather the 6,869 registered voters' signatures required to put a charter amendment proposal on the ballot this November. They said they hit that number within a few weeks, but kept up the petition drive.

Now, the signatures will be examined by city officials. If they pass the required threshold, they'll be forwarded to the City Council, which will determine if the proposal is a valid charter amendment and should be put on the ballot.

Standing on the steps of the City Hall rotunda, dozens of workers and organizers with the groups 15 Now, Neighborhoods Organizing for Change and Centro de Trabajadores Unidos en Lucha (CTUL) applauded as organizers of the effort said they were confident a $15 minimum wage would be approved — and that they had the legal standing to call for a vote.

"Big business will fight to keep us off the ballot every step of the way," said Ginger Jentzen, an organizer with 15 Now. "But let's be clear: it is not a matter of opinion if we have this right."

The proposal would amend the city's charter — the document that lays out the powers and functions of city government — to require all businesses to begin to raise wages starting next year. Businesses with 500 or more employees would pay at least $10 per hour starting in August 2017, with the number increasing each year to $15 in 2020. Smaller businesses, meanwhile, would get more time, raising wages incrementally until they reached $15 per hour in August 2022.

As Steven Suffridge became the 20,001st person to sign, Ginger Jentzen held a stack of petitions backing a $15 minimum wage.

In a statement issued after the signatures were turned in, Downtown Council President and CEO Steve Cramer called on officials not to "allow the city's charter to be misused."

"Minneapolis business owners should not be subjected to yet another unique mandate only in our city, especially since a recent statewide approved increase is still being implemented," he said.

City Attorney Susan Segal has not issued a formal opinion on whether the city can raise the minimum wage, or if the issue can be decided through a charter amendment. A few City Council members have expressed concerns about those legal questions, and the chairman of the city's Charter Commission has said he doesn't believe the issue can be decided with a charter amendment.

Some supporters at City Hall on Wednesday said legal questions from the city amount to attempts to deny workers the right to vote on the issue. They said low wages are contributing to the city's glaring racial and economic disparities, and that the issue needs to be tackled now.

"People say it's not the right time," said Rod Adams, an organizer with Neighborhoods Organizing for Change. "But you tell me: When's the right time for families to go hungry? When's the right time for people to go without electricity?"

Erin Golden • 612-673-4790