Delaware County’s independent public wastewater authority on Monday moved to block the county’s attempt to take over its operations, calling the move an “illegal money grab” of proceeds from the authority’s pending $276.5 million sale to private operator Aqua Pennsylvania.

The Delaware County Regional Water Quality Control Authority, or DELCORA, filed for a preliminary injunction to block the takeover attempt ahead of Wednesday’s scheduled vote by the County Council to terminate the authority and to assume operations under the county’s control.

DELCORA, in documents filed with the Delaware County Common Pleas Court, said the transfer of the authority is illegal because it requires the advance approval of state and federal environmental regulators, as well as the Pennsylvania Public Utility Commission (PUC). It said the takeover would also violate state law, which prohibits the termination of a municipal authority while it has outstanding bond debt. DELCORA has about $170 million in debt.

The ordinance scheduled for a vote this week “would blatantly violate existing law and needlessly create a nightmare scenario of irreparable harm that jeopardizes wastewater conveyance and treatment services for the citizens of Delaware County and beyond,” the authority said in its request for a preliminary injunction.

DELCORA’s legal action is the latest escalation in a politicized battle over the sewer authority, which was created in 1971 and controlled for almost all of its existence by the county’s entrenched Republican Party. Last year the County Council, facing an imminent change of political power in the November election, moved to sell the sprawling public sewer system to Aqua Pennsylvania, the company that provides drinking water service to much of the county.

Aqua Pennsylvania, a subsidiary of Bryn Mawr-based Essential Utilities, says it has a sales agreement with DELCORA that Delaware County cannot break. “We intend to enforce the contract and proceed with the sale,” the company said in a statement.

The sale of DELCORA, which serves 165,000 customers in 42 towns in Delaware and Chester Counties, has not yet closed and is pending approval by the PUC. The complex transaction has become even more complicated with the involvement of warring political parties over who has the power to authorize the sale.

DELCORA executive director Robert J. Willert, who is also president of the Ridley Township Board of Commissioners and head of the township’s Republicans, called on the county to postpone the Wednesday vote and conduct public hearings to review the county’s plan for operating the system and determine what is in the best interest of DELCORA’s ratepayers.

“The public deserves to know council’s plan and to provide comment on it,” Willert said in a statement.

The newly installed Democrats last month introduced legislation to terminate DELCORA and also filed suit challenging DELCORA’s creation of a trust that would hold the proceeds from the sale. The trust — a critical part of the deal the outgoing Republicans structured — would use the proceeds from the sale to reduce the impact of expected rate increases on consumers.

DELCORA, in its request for an injunction, alleged that the county’s proposed ordinance is designed to retain the funds from the sale rather than use them for rate relief. “Council’s attempt to terminate DELCORA via the ordinance is simply part of its efforts to keep that money for itself,” it said in the court filing.

The county, through a spokesman, said Monday that it would move ahead with plans to dissolve DELCORA and return the authority to its “rightful owners," the people of Delaware County.