ATTLEBORO - A sweeping urban renewal plan meant to reshape and revitalize downtown with transportation improvements, condominiums and commercial development was discussed at a three-hour public hearing Tuesday, signaling the beginning of a crucial decision-making process for the city.

The hearing, held before the city council and planning board, will likely be closed next week and the boards will then begin deliberations and move toward what one councilor called a vote of "historic proportions."

That vote is not likely to take place until mid-March, said Councilor Frank Cook, who is charged with guiding the measure through the council's committee process.

The plan was proposed by the Attleboro Redevelopment Authority with strong backing of Mayor Kevin Dumas.

Cook said the goal is to be thorough, but to move as quickly as possible to satisfy federal authorities who have warned that $10 million already earmarked for the project could be at risk unless the city takes action soon. "I want to move as expeditiously as possible and as carefully as possible," Cook said. "This is a vote of historic proportions, and probably the most important vote we'll ever be asked to make."

Cook plans to call for a special committee meeting that would be dedicated to discussing the plan in detail. Discussion in committee could take another several hours, he said.

The plan would take 26 acres between the Ten Mile River and the Amtrak railroad tracks and transform it into a kind of urban village with close ties to trains, buses, recreation and - most importantly - downtown.

But action must come soon.

U.S. Rep. Jim McGovern, D-Worcester, has told the city he can't seek more money until progress is made. And he can't guarantee the $10 million already earmarked.

He wants to see the urban renewal plan passed and a commitment to fund the city's share of the first phase. He said the latest action could take place is March.

Dumas said recently that he has been in contact with McGovern, and believes that as long as the city keeps moving forward it should be enough to retain the backing of the congressman.

The urban renewal plan seeks only to implement the first phase of a massive $61 million project that covers five downtown districts.

Phase 1A costs about $14.7 million and the city would have to pay about $2.4 million of that cost. It's comprised of two districts, a 26-acre parcel that includes the current location of the public works yard and the six-acre site of the former Swank Co. property on Pearl Street, which is being converted for use by Cookson Precious Metals.

There was no outright opposition to the plan Tuesday. Francis Balut of Carrier Avenue came the closest. He took issue with the financing predictions and suggested inflation figures weren't high enough.

"If there is some doubt, my opinion is to wait," he said.

Meanwhile, two property owners argued that the ARA has treated them unfairly.

Trip Richardson, owner of a one-acre industrial site, said ARA negotiations have stalled his plans for development of the land; and the owners of Reynolds and Markman said an ARA offer for that property would put the financial stability of the business in danger.

GEORGE W. RHODES can be reached at 508-236-0432 or at grhodes@thesunchronicle.com.