Erie County voters will get a chance later this year to downsize their County Legislature to 11 members.

Lawmakers set the stage for a ballot referendum on downsizing after voting Thursday to reduce the size of their 15- member body.

The measure, one of four considered by lawmakers, also has the backing of County Executive Chris Collins, who vetoed a different downsizing measure last year.

“Is there anyone out there who doesn’t realize our population is declining?” said Legislator Thomas A. Loughran, the Amherst Democrat who sponsored the current bill. “We’re hemorrhaging.”

The legislation, if approved by voters, would eliminate four legislative seats but, unlike last year’s downsizing measure, keep legislators’ terms at two years, not four.

The 9-6 vote in favor of downsizing was the result of six Republicans and three Democrats joining forces to get the bill passed.

The bipartisan coalition held together as lawmakers entertained two competing proposals, one for nine members with two-year terms and another for 11 members with four-year terms. Both measures failed.

“If this isn’t real reform, I don’t know what is,” said Republican Edward A. Rath III of Amherst. “This is real, this is significant, this is tangible.”

Opponents argued that with the downsizing will come a loss of representation, especially for minority voters in the City of Buffalo.

“Downsizing by four?” said Democrat Betty Jean Grant of Buffalo. “Are we going to risk losing all those voices for Buffalo?”

Others wondered aloud if the outcry for downsizing is real or imagined.

“I don’t hear this from my constituents,” said Democrat Lynn M. Marinelli of the Town of Tonawanda. “I simply don’t, and I pride myself on my door-to-door [contact with district residents].”

The debate over downsizing the County Legislature dates back years, even decades, and began to resurface when Legislature Republicans pushed the notion of a nine-member Legislature three years ago.

The effort failed, but county lawmakers responded by forming a citizens commission to look at the size and makeup of the Legislature. The commission recommended an 11-member body with members serving four-year terms.

The Legislature stopped well short of that suggestion last year and instead recommended a 13-member body with four-year terms.

Collins, unhappy with the longer terms, vetoed the measure, and the Legislature failed to override him.

This year, Collins counts himself as a downsizing supporter, in large part because the new initiative is no longer tied to longer terms.

“We’re pleased that nine members passed this significant downsizing measure,” Collins spokesman Grant Loomis said Thursday.

Loomis said Collins will sign the legislation, paving the way for a countywide proposition on the November general election ballot.

The downsizing movement has gained momentum over the past year with several Erie County towns deciding smaller is better.

Amherst became the latest town to join the downsizing band wagon. In January, the Town Board unanimously approved a local law that would eliminate two board seats over the next four years. The measure now goes to Amherst’s voters.

Downsizing advocates attribute their success to the growing belief that the large number of elected leaders here is an impediment to reform and savings. They argue, for example, that most elected officials tend to protect their turf and patronage.

“We’re just going to have to work a little harder to represent our constituents,” Republican John J. Mills of Orchard Park said of a smaller County Legislature.

Opponents are quick to note that the County Legislature has already downsized from as many as 21 members.

They also claim a smaller Legislature will weaken minority representation because legislative districts will hurt Buffalo and favor the more heavily populated suburbs.

Some even suggested the Legislature wait until after the 2010 Census count decides the population of each municipality in Erie County.

“We’re putting the cart before the horse,” said Democrat Maria Whyte of Buffalo.

Whyte was one of six Democrats to vote against the downsizing measure. The others are Grant, Marinelli, Barbara Miller- Williams of Buffalo, Daniel M. Kozub of Hamburg and Thomas J. Mazur of Cheektowaga.