Department of Defense officials on Monday delivered computer discs to a congressional committee containing thousands of pages related to the base closure and realignment process.

Sens. Susan Collins, R-Maine, and Joseph Lieberman, D-Conn., had issued a subpoena last week seeking base closing data. The two said they and other supporters of targeted bases in their states need the documents to make a case for saving the bases.

“While it will take time to go through the documents, the information they provided us today appears to be new and significant – and it is information that we otherwise would not have had without the subpoena,” Collins said.

The deadline for releasing the documents was noon Monday, but the senators had agreed to extend it to Friday because the Pentagon was making progress.

In issuing the subpoena, Collins and Lieberman said that under the law governing the base closure process, the documents already should have been released. Collins is chairwoman of the Homeland Security and Governmental Affairs Committee, while Lieberman is the ranking Democrat.

The independent commission reviewing the Pentagon’s base closure proposals agreed to delay regional hearings last week after dozens of senators complained they needed more time to review new data justifying the plans.

The subpoena demanded data including spreadsheets, e-mails, memoranda, handwritten notes and telephone logs. Collins had said she was willing to negotiate with the Pentagon over materials including phone records and e-mails.

Collins and Lieberman represent the two states that would suffer the biggest job losses if the recommendations of the Base Realignment and Closure Commission are followed.

The Navy’s submarine base in Groton, Conn., would close. Maine would lose the Portsmouth Naval Shipyard and all of the aircraft and half of the military personnel at the Brunswick Naval Air Station.

Maine also would lose a military processing center in Limestone.