Arguing that a union petition asking the Public Service Commission to force Consolidated Edison Inc. to end its lockout of 8,500 workers has “no basis in law,” the company Tuesday asked the regulatory body to deny the motion in its entirety.

Local 1-2 of the Utility Workers Union of America last week asked the Public Service Commission to end the lockout, now in its third week, and to investigate the quality, reliability and safety of the service being provided while 5,000 managers and additional outside contractors are doing the jobs of unionized workers. The regulatory body had given Con Ed until Tuesday at 4:30 p.m. to respond.

The utility giant submitted a 62-page document reiterating its stance that it had to lock out its workers because their union refused to warn of any potential strike. “Advance notice is absolutely critical for the safe and seamless operation of our systems,” the response said.

The union has said that promising notice would have taken away its main weapon in bargaining. A spokesman for Local 1-2 reiterated that the union did not strike and that its members were locked out.

Con Ed argued that any investigation by the commission would be tantamount to interfering in the collective bargaining process, from which the panel has historically steered clear.

A spokesman for the commission said it is reviewing Con Ed’s response.

The reply lays out the company’s contingency plans for the lockout. Con Ed said it spent a year updating its plan, which identified key tasks and staffing levels needed to keep its electric, gas and steam systems functioning.

“Now in its third week, the contingency plan is working,” the company’s response said. “Our systems remain reliable, despite the extreme heat.”

Con Ed said it was able to deal with its fourth-highest weekend load ever during the early July heat wave without incident.

Its 5,000 managers are working 12-hour days, six days a week, according to the company. About 685 outside contractors and retirees are augmenting that workforce. Regular maintenance and inspections have not been affected, the response claims.

It goes on to blame the union for blocking the delivery of key equipment needed in Con Ed’s Bensonhurst, Brooklyn, substation and for blocking fuel deliveries to generators that are helping to keep power on in several Brooklyn neighborhoods while a transformer is being replaced.

A spokesman for Local 1-2 said that union members were exercising their right to set up picket lines. “We have a legal right to picket,” he said. “They better think of a better way than using scab labor to take bread out of the mouths of 8,500 New York families.”

The workers have had their health benefits restored by the company through at least the end of the month.

Con Ed released its response as thousands of union members rallied in Union Square for an end to the lockout. Organized by the state AFL-CIO and the New York City Central Labor Council, the rally drew retail workers, teachers, construction workers, building workers, firefighters, transit workers and health care workers, among others. “We expect the PSC will see through [Con Ed’s] smoke-and-mirrors approach to corporate responsibility,” said state AFL-CIO President Mario Cilento.