Members of the City Council plan to investigate allegations that a private company with a contract to handle city 311 calls is trying to stymie its employees’ efforts to unionize.

Council Members Gale Brewer, chairwoman of the council’s technology in government committee, and Joseph Addabbo Jr., chairman of the civil service and labor committee, told The New York Sun they were looking into claims made by the Communications Workers of America Local 1180 and would schedule a joint oversight hearing if necessary.

The union is accusing King TeleServices of aggressive anti-union tactics and of “picking off” employees who support organizing. The company, based in Long Island City, Queens, has a city contract worth up to $9 million to field a portion of 311 calls,

Though officials at King TeleServices acknowledge their opposition to the union, they deny strong-arming employees or meeting with them individually to discuss the union.

The chairman of King, Peter Harkins, said the situation, which was first reported Monday in the Sun, did not warrant an investigation, but he said the company would cooperate.

“We welcome any inquiry into the issue,” Mr. Harkins said yesterday during a phone interview. “We know the fact and we are very comfortable with the record.”

Ms. Brewer, a Democrat who represents the Upper West Side, said she was phoning the involved parties and would probably request a hearing.

Mr. Addabbo, a Democrat of Queens, said he was trying to get more information on the matter and would decide how to proceed from there.

“Minimally, the administration should be concerned,” he said. “They shouldn’t just wipe their hands clean and say this is a dispute between a private company and their employees.”

The local submitted a petition to hold an election but withdrew it on December 22. A field organizer for the organization, Chris Aiken, said the local had the required 30% support needed to qualify for an election but pulled the petition because King diluted its chances of garnering the 50% of the vote it needs.

King officials have sent their 311 employees five memos in the past few weeks, urging opposition to affiliation with the union. They insist, however, that they respect the union’s organizing process and are just voicing the other side of the story.

“At the end of the day,” Mr. Harkins said, “The issue of union representation is going to be decided by the employees, but we think the reason why the CWA withdrew their petition was that they lacked the requisite level of employee support to win.”

Mr. Harkins also questioned whether the local would respect the outcome if a clear majority of workers decided they wanted to keep a nonunion shop.

He pointed to the 239 phone messages left for Mayor Bloomberg demanding that King allow a “speedy union election.” Those messages, which followed a script, were left with the 311 helpline.

According to statistics provided by King, more than 75% of the calls came from outside New York City. In an email, Mr. Harkin sent the Sun earlier this week, he said only one of the approximately 152 operators working on 311 at King lives outside the city. The breakdown shows 17 calls from California, 15 from Texas, 9 from both Virginia and Michigan, and dozens from elsewhere in the country.

Mr. Harkins said the calls bear no reflection on whether his staff supports the union. Mr. Aiken stood by his original accusation against King and said there was nothing wrong with messages from members of the national union to show support for fair wages and benefits at King.

The city has roughly 200 of its own 311 employees at a site on Maiden Lane at Lower Manhattan.

Sources, who would not go on the record, said the city plans to take on more call volume and relinquish some of its reliance on the private company.

Still, CWA, which represents some of the city employees at the 311 center, said King workers should be paid comparably if they are doing the same work. There is some dispute as to exactly how much less King employees are paid.

Earlier this week, the Bloomberg administration, which has touted the success of 311, stressed that the dispute did not involve the city.

The commissioner of the city’s Department of Information and Technology and Telecommunications, Gino Menchini, said he did not have all the facts but said the right for employees to organize should never be “tinkered with.”