AUGUSTA — A coalition of advocacy groups seeking to restore election-day voter registration in Maine launched a signature-gathering effort today in hopes of forcing a referendum as early as November on the issue.

The newly formed Protect Maine Votes Political Action Committee held news conferences in Bangor, Lewiston and Portland to kick off a voters’ signature collection drive, which organizers said will have a presence this weekend in 11 of Maine’s 16 counties. Using the people’s veto provision in the state Constitution, the organizers want to force a referendum on whether to repeal a law that was enacted during the late days of this year’s legislative session.

The new law says voters must be registered no later than two business days before an election. Supporters said many municipal election officials lack the staff to accommodate an ever-increasing number of last-minute registrations.

The issue has political overtones, as the new law to get rid of Maine’s same-day registration law won passage with support of the Republican majority and opposed by Democrats. To force a referendum in November, the coalition must collect a minimum of 57,277 voters’ signatures by Aug. 8 — exactly a month away.

If they fail to do that, the forces to restore same-day registration would still have until Sept. 27 to turn in the signatures for a referendum in June 2012. For now, coalition members are focused on November.

“We have an aggressive signature-gathering process in place that targets the November ballot,” campaign spokesman David Farmer said. But Farmer said organizers were realistic about the difficult challenge of rounding up the needed signatures by Aug. 8. He said the campaign is prepared to extend its effort toward a June vote.

Coalition members, who include the Maine Civil Liberties Union, Maine League of Conservation Voters, League of Women Voters of Maine, Maine AFL-CIO, Maine People’s Alliance, EqualityMaine, Maine Education Association and Homeless Voices for Justice among other organizations, say the revised law wipes out a 38-year tradition of election-day registration that helps to keep Maine among the states with the highest turnouts.

“It’s part of our heritage as a state that values local participation, town meetings and local control. The Legislature should not have taken that basic democratic right away from Mainers,” said Mark Gray, campaign manager for Protect Maine Votes.

While no opposition campaign has surfaced, Maine Republican Chairman Charles Webster said a coalition will be organized if the signature-gathering effort succeeds.

“I’m just stepping back and seeing what they do,” Webster said. Before the end of the month, Webster said his side will hold a news conference to discuss voting abuses he says have occurred under the same-day registration law.

Webster also believes that same-day registration is not a priority issue for most Mainers.

“It’s not an issue that working people, regular people, are concerned about,” he said.

Maine’s chief election official, Secretary of State Charles Summers, has approved the wording of the referendum question if the people’s veto effort forces a vote: “Do you want to reject the section of Chapter 399 of the Public Laws of 2011 that requires new voters to register to vote at least two business days prior to an election?”