Labor turned on itself Monday, as the dispute over work rules at the Convention Center resulted in rival union leaders deriding one another.

John Dougherty, leader of International Brotherhood of Electrical Workers Local 98, accused the Teamsters and Carpenters of failing the city and their members. William Hamilton, leader of Teamsters Local 107, called Dougherty "an embarrassment."

A spokesman for Local 8 of the Metropolitan Regional Council of Carpenters dismissed Dougherty as a union leader who crossed a picket line.

The remarkable display of bitterness was triggered when leaders of three of the four unions still employed at the Convention Center personally shepherded their members across a picket line early Monday as the facility reopened under new work rules.

The picketing unions, representing the Carpenters and Teamsters, later filed an unfair labor practice charge against the Convention Center management with the National Labor Relations Board.

About 7:30 a.m., Dougherty of the IBEW, Sam Staten Jr. and Ryan Boyer of Laborers Local 332, and Michael Barnes of Stagehands Local 8 joined about 30 members of their unions going into the hall to begin work on exhibits for the 2014 BIO World Congress on Industrial Biotechnology.

They were jeered by about 30 Teamsters, who, along with the Carpenters, had been displaced from the center because their leaders did not sign new work rules by last week's deadline. Monday was the first day of work with the Teamsters and Carpenters forced to the sidelines.

Later, in interviews, Dougherty and Hamilton blamed each other for the clash among unions.

"It's one thing to sign an agreement and have your people go to work, and it's another thing to wave it in people's faces and actually make a spectacle of it," Hamilton said. "It's an insult to labor. 'Johnny Doc' might be a Philadelphia legend in his own mind, but he's an embarrassment."

Dougherty said that if anyone had let down labor, it was Hamilton, when he failed to sign on to a work rules agreement demanded by the Convention Center.

"I was there today because I knew they were going to try to embarrass people," Dougherty said of the demonstrators. "It was all because Billy Hamilton knows he made a mistake. It shows his total lack of representation of his membership."

Dougherty also was critical of the leadership of the Carpenters. That union, like the Teamsters, has been removed from the workforce after failing to sign the new work-rules agreement.

"Everybody knows that for the past 10 years, there has only been one problem at the Convention Center, and that's the Carpenters," Dougherty said, blaming that union for the difficulties that have driven trade shows from the center because of high costs and problematic behavior from some workers.

The Carpenters' behavior, Dougherty said, was a "complete affront to the hospitality industry, all the new restaurants in town, all the new developments, every chambermaid, every person who wants to make Philadelphia a better place to live and work."

In response, a spokesman for the Carpenters pointed to Dougherty's decision to cross a picket line.

"Ed Coryell did not cross a picket line," said Martin O'Rourke, referring to the Carpenters' executive secretary and treasurer.

Despite the dispute, the day was remarkably subdued at the complex itself.

Whatever discord was happening outside the building, there was nothing but harmony inside, said Michael Barnes, the Stagehands' leader.

"I think it went smoothly," he said. Minor problems, he said, disappeared. For example, he said, under previous work rules the Laborers would hang the pipe borders between exhibitors' stands. Then the Carpenters would have to take down the pipe borders, thread the pipe through the draperies, and rehang them, requiring the same piece of pipe to be handled twice.

On Monday, Barnes said, "it was a lot simpler, a lot easier, and a lot more efficient."

The new work rules were adopted by the Convention Center board of directors to address exhibitor complaints about labor costs and inefficiencies. They said the facility has been losing shows to other cities as a result.

The rules were agreed to by the Electricians, Laborers, Stagehands and Iron Workers after the Convention Center set a signing deadline of May 5. The Carpenters and Teamsters contended that they were misled about the deadline.

The Carpenters and Teamsters, in their labor practice complaint, said the Convention Center's management had "engaged in bad faith bargaining."

The documents seek an injunction and are filed against the Pennsylvania Convention Center Authority as well as its management company, SMG, and its labor broker, Elliott-Lewis Corp.

The NLRB filing repeats the Carpenters' argument that they believed they had a contract extension until Saturday, and that the customer satisfaction agreement was included in that span of time.

Convention Center spokesman Pete Peterson said: "The center management has not yet had the opportunity to review the filing. However, we are confident that we have followed both the letter and spirit of the law."