Voters would decide whether two seats on the 15-member Erie County Legislature should be eliminated under a downsizing plan lawmakers approved Thursday in a 14-0 vote.

The proposed local law includes a provision that would double the length of legislators’ terms to four years, a move that County Executive Chris Collins has branded as “sneaky.” Collins supports shrinking the size of the Legislature, but he said he would veto the proposed law because voters should be given a chance to decide each change separately.

If legislators maintain the votes to override a veto and the referendum is approved in November, the changes would take effect in the 2011 election cycle.

Two other downsizing models that would have eliminated even more seats failed to snare enough support Thursday and were taken off the table. One plan would have reduced the body to nine members, and the other—11 members—a plan that was favored by a citizens’ panel created by the Legislature to recommend reforms. “I’m disappointed that they didn’t let the 11-member [plan] go to the voters,” said Martha Lamparelli, chairwoman of the 21st Century Commission. “But I’m glad to see that at least they’re looking at a reduction.”

Legislature Chairwoman Lynn M. Marinelli, D-Town of Tonawanda, said the 13-member model was key to reaching a consensus on the oftentimes contentious issue of downsizing. “In any legislative body, you need a majority to get things done,” she said.

But critics said eliminating only two seats amounts to “nibbling around the edges.” “It’s a minor change to placate the masses so we can look good at the ballot box this year,” said Amherst Republican Raymond W. Walter.

Minority Leader John J. Mills, R-Orchard Park, said he believes there would be county-wide support to eliminate six seats. Some alluded to recent actions by voters in West Seneca and Evans to cut two members from each of their town boards.

“This community is screaming for change,” said Amherst Democrat Thomas A. Loughran, who was among several lawmakers who wanted to place all three downsizing plans on the ballot.

Others warned against putting more than one proposed reduction before voters.

“What happens if we get a tie?” asked Lackawanna Democrat Daniel M. Kozub. “What happens then? Do we flip a coin?”

Eliminating more than two seats could subject the county to future lawsuits and create unwieldy districts, critics contended. Robert B. Reynolds Jr., a Hamburg Democrat, said some lawmakers already represent districts that stretch across large areas.

Some legislators who supported putting the 13-member model on the ballot said they hope voters reject it in the fall.

“Fifteen is a good number,” said Buffalo Democrat Betty Jean Grant. “We’ve downsized twice in the past 24 years.”

The Legislature once had 20 members. It was reduced to 17, then to its current 15 members.

Lamparelli also criticized the decision to link the downsizing with a plan that would double the length of lawmakers’ terms to four years. While the citizens’ panel supported the change, Lamparelli agreed with Collins that the two issues should be presented to voters as separate laws.