The vitriol displayed Monday by some of the city's most prominent labor leaders apparently has roots in a political battle last year over Gov. Corbett's $2.3 billion transportation bill.

At the time, a number of key unions - including Electrical Workers Local 98 and Laborers Local 332 - lined up behind the bill, which is expected to create a flood of jobs while funding bridge and road repairs.

However, Local 8 of the Metropolitan Regional Council of Carpenters, whose representatives declined to comment for this article, opposed the bill, citing a wage provision within it.

While the bill ultimately passed, John "Johnny Doc" Dougherty, business manager of the Electrical Workers, still chafes at the position of the Carpenters leaders, which he believes would have denied work for his members as well as their own.

"There is a pattern developing of pettiness and bad politics that are costing their own members job opportunities," Dougherty said.

The dispute also caused a rupture between the Carpenters and the Philadelphia Building and Construction Trades Council, which supported the bill.

As the bill was debated, the Carpenters stopped contributing dues to the council, a budget-disrupting move that was seen as retaliatory. "We missed some paydays," said Pat Gillespie, business manager of the trades council. "We missed some pension payments. We will get by."

The bad blood apparently continues, according to Gillespie, with Carpenters crossing council members' picket lines at work sites in King of Prussia and South Philadelphia this week. While the Carpenters have resumed paying dues, they are paying only a fraction of their previous contributions, Gillespie said.

"I hate to see it come to this," he said. "It is not too draconian for me, but it is awful for the people who work for me."

The Carpenters and Electricians are on opposite sides of the dispute at the Convention Center over new work rules. Four of the six unions that did work at the center signed new contracts that include Customer Satisfaction Agreements. The Carpenters and the Teamsters did not sign before deadlines passed last week. As a result, their work is being assumed by the four signatory unions, which also include Stagehands Local 8 and Iron Workers Local 405.

On Monday, the Carpenters and Teamsters each filed unfair labor practice complaints with the National Labor Relations Board. They contend that the center did not have the authority to unilaterally demand a decision on the work rules while the unions were continuing to negotiate new contracts.

Daniel E. Halevy, regional attorney for the NLRB, said the matter would be given priority status. He declined to say how long the process might take.

Tuesday was quiet at the Convention Center, with no labor unrest. That is in contrast to Monday morning, when leaders from the Electricians, Laborers, and Stagehands led union members across Carpenters and Teamsters picket lines. That triggered much animosity and bitter words.

Michael Barnes, president of the Stagehands, said he supported the new work rules, designed to make the Convention Center more competitive with other large convention facilities nationally. Barnes felt he had no choice but to have his members cross the line and go to work.

"My only other option was to not sign the deal and have my guys lose out on their second-biggest employer," he said. "We weren't prepared to do that."

Dougherty on Monday had blamed problems at the center on the Carpenters, whose actions, he said, were costing union jobs across the board.

That echoed his position in November, when the transportation bill was in the balance. That bill provided $1.65 billion for bridge and road repairs statewide and $500 million for mass transit projects.

The Carpenters opposed a provision that modified wage requirements on smaller government-funded projects to reduce labor costs. Gillespie called the provision a minor concession in a bill that would be a boon for labor.

Dougherty said he was primarily interested in ensuring that mass transit be funded. He said he believed the $500 million dedicated to mass transit would be a precursor to his goal of seeing the Broad Street Subway extended to the Navy Yard.

"That will be a game-changer for Philadelphia," Dougherty said. "Before the transportation bill, it did not seem a possibility. Now it is closer to a reality."