AUGUSTA, Maine — A referendum question that would raise Maine’s minimum wage to $12 per hour by 2020 qualified for the November ballot, the secretary of state’s office said Tuesday.

The effort was led by the progressive Maine People’s Alliance and it could set off a bid from pro-business groups to get the Maine Legislature to put a proposal for a smaller increase on the ballot as a competing measure.

The plan would increase Maine’s minimum wage of $7.50 per hour to $9 in 2017, then by an additional $1 each year until it reaches $12 in 2020, after which it’ll be indexed to inflation. It would also raise Maine’s tipped minimum wage from $3.75 per hour to $5 in 2017, after which it will rise each year until it reaches the non-tipped minimum wage.

The Maine People’s Alliance and labor unions announced the bid last year, with Matt Schlobohm, the Maine AFL-CIO’s executive director, saying “wages haven’t come close to keeping up” with increasing costs of living in Maine.

Now, the bill goes to the Legislature, which can either enact it or send it to the voters. But it can also advance a competing measure. That’s where the Maine State Chamber of Commerce could look for a way to beat the effort back.

Peter Gore, a lobbyist for the group, said earlier this month that the increase would be “particularly difficult for small businesses in this state to swallow,” and he said it may press the Legislature to put a smaller increase on the ballot, but that nothing has been decided yet.