The Justice Department released a new set of FBI investigative guidelines on Friday, despite misgivings about them on Capitol Hill.

Attorney General Michael B. Mukasey has decided that the guidelines, which do not need congressional approval, will take effect Dec. 1. They will allow the FBI to use, across all types of investigations, investigative tools and techniques previously segregated among criminal, national security and foreign intelligence matters.

The guidelines would allow the FBI to use some techniques — such as grand jury subpoenas for telephone or e-mail subscriber information — without any evidence of wrongdoing.

“We are confident these guidelines will assist the FBI in carrying out its critical national security and foreign intelligence missions while also protecting privacy and civil liberties,” Mueller and Mukasey said in a joint statement Friday.

Some lawmakers have complained that they were not adequately consulted about the guidelines before Mukasey moved to implement them. Civil libertarians have worried that the guidelines could allow the FBI to be overly intrusive.

“It appears that with these guidelines, the attorney general is once again giving the FBI broad new powers to conduct surveillance and use other intrusive investigative techniques on Americans without requiring any indication of wrongdoing or any approval even from FBI supervisors,” said Senate Judiciary Chairman Patrick J. Leahy , D-Vt.

Leahy said the committee would give extensive oversight to the new guidelines in the next Congress.

FBI Director Robert S. Mueller III was questioned about the draft guidelines during House and Senate Judiciary oversight hearings last month. He told lawmakers that the guidelines did not give the bureau any new powers.

“We are confident these guidelines will assist the FBI in carrying out its critical national security and foreign intelligence missions while also protecting privacy and civil liberties,” Mueller and Mukasey said in a joint statement Friday.