A handful of Eastside politicians, including Redmond Mayor John Marchione, joined with regional business, labor, and government leaders Thursday to support moving ahead with construction of the state’s preferred six-lane 520 bridge replacement.

The group’s press conference came on the heels of another coalition’s proposal to revise that plan, as recommended by Seattle Mayor Mike McGinn.

McGinn is pushing to eliminate two proposed carpool lanes that are part of the plan in exchange for two dedicated transit lanes.

Bellevue City Councilmember Grant Degginger said he doesn’t want to see any delays. He took part in the move-forward coalition’s Thursday press conference at the Museum of History and Industry in Seattle.

“The time for study is over, and the time for construction is now,” Degginger said. “It’s critically important for the region that this move ahead.”

Others joining the move-forward coalition on Thursday included Seattle City Council President Richard Conlin, Greater Seattle Chamber of Commerce president and CEO Phil Bussey, Rep. Deb Eddy of the 48th Legislative District and Marchione.

Representing labor was Lee Newgent, executive secretary of the Seattle Building and Construction Trades Council, who said Washington needs the jobs that a 520 replacement project would create.

Newgent also said that delaying construction to do additional planning and study would increase the cost of building the bridge by 15 to 30 percent.

“Right now, the price of construction in the state of Washington is at an historic low,” he said.

But opponents say the state needs to plan the right project before forging ahead.

A group called Coalition for a Sustainable SR 520, which represents Seattle neighborhoods like Montlake, Portage Bay and Roanoke Park, supports McGinn’s proposal for a six-lane corridor with two lanes dedicated to transit.

“If we build for cars, we’ll be inviting more traffic into the city,” said Fran Conley, a member of the group. “The question is: how do we build a transportation corridor for the rest of the century, not how do we build a bigger highway?”

A group of state lawmakers in January unveiled its preferred design for the bridge replacement, calling for Option A+.

That plan would create a new Montlake interchange at the same location as the current one, while adding a second draw bridge parallel to the Montlake Bridge.

House Speaker Frank Chopp has come out against Option A+, saying the plan doesn’t offer enough mitigation for impacts to local neighborhoods. He also cited concerns that a new drawbridge would delay buses moving to the future University of Washington light-rail station.

King County Metro Transit has given its blessing to Option A+, as has the county itself.