PORTLAND (AP) – A ballot measure that would extend Maine’s legislative term limits from four to six consecutive terms picked up support from civic activist groups Thursday, a day after opponents released a study which says the present term limits law is working fine.

Common Cause Maine and the League of Women Voters of Maine were joined by other groups to announce their support for the proposal, which would let lawmakers serve a maximum of 12 years in a row instead of eight in either the Maine House of Representatives or Senate.

The proposal, sent to voters by the Legislature, would modify the law enacted as a result of a 1993 referendum. It will appear as Question 5 on next Tuesday’s statewide ballot.

Alison Smith of the League of Women Voters called extended term limits a moderate reform that will address adverse effects of the present law.

“By disqualifying legislators who have been able to gain skill through experience, term limits dilute the effective performance of the Legislature and weaken their role in crafting sound policy solutions to complex problems,” Smith said at a news conference with other groups at the University of Southern Maine.

Smith said extended term limits will do nothing to guarantee the re-election of incumbents.

“Maine voters have always had the opportunity to retire legislators who do not adequately represent their districts,” said Smith, adding, “we do that through elections.”

Jon Bartholomew of Common Cause Maine said his primary concern about term limits is “the lack of accountability that comes from the shift of power from the legislative branch to the executive branch and lobbyists.”

“We can hold bad legislators accountable every two years on Election Day, but we can’t hold lobbyists or agency staffers accountable,” said Bartholomew. He believes that passage of Question 5 will enable lawmakers to gain more from their experience and rely less on lobbyists and bureaucrats.

“If you think our Legislature is working great now, then vote no on Measure 5. If you think our Legislature could function better, then vote Yes on Measure 5,” said Bartholomew.

Present term limits have created a leadership structure that has too little time to build consensus necessary to address some of the state’s most pressing problems, said Christopher St. John of the Maine Center for Economic Policy, who has observed the Legislature for nearly three decades.

The supporters, who also include the Maine People’s Alliance, spoke a day after the conservative Maine Heritage Policy Center released a new study highlighting the positive effects of Maine’s current term limits.

Tarren Bragdon, director of Heritage Policy Center’s health reform initiatives, said the study shows that more legislators are now serving with midlevel experience. Nearly two-thirds of legislators serve for at least six years, and there is more access to leadership positions, under present term limits, he said.

The analysis shows that before term limits, 23 percent of elected state representatives had eight or more years of previous legislative experience. Just over a fourth of the members were newly elected with no prior legislative experience, while the rest had between two and seven years of experience.

Of the 28 percent of members newly elected with no prior experience each session, less than half remained there for at least six years of service, says the analysis, which was done by Bragdon and Stephen Bowen, who like Bragdon is a former state representative.

But after term limits, the authors said, experience was more evenly spread, with a third of members newly elected, a quarter having served two years previously, a fifth have served four years previously and a sixth with six years of experience.

“Prior to term limits the Maine House resembled a seniority-driven bureaucracy where all the authority was coalesced by a small group of long-serving legislators, ‘power brokers,”‘ said Bowen. “With term limits, the Maine House resembles a small dynamic company with open access to decision making.”