Current and former judges on the nation’s secret surveillance court said in a letter released Tuesday that several recommendations made by a White House review group would significantly increase the court’s workload and undermine its effectiveness.

The letter, written by the court’s former chief judge, John D. Bates, was released by the chairman of the Senate intelligence committee three days before President Obama is due to give a major speech outlining his reforms for U.S. surveillance policies — some of which, the intelligence community has argued, could harm national security.

It came on the same day that members of the presidentially appointed review group, whose 46 recommendations were released last month, appeared before the Senate Judiciary Committee.

The judges’ principal objections focused on recommendations to appoint an independent privacy advocate to represent the public’s interests before the court and on a proposal that administrative subpoenas, known as national security letters, be approved by the court before being issued. They also objected to a recommendation to end the National Security Agency’s bulk collection of data on Americans’ phone calls.

Obama himself had advanced the idea of a public-interest advocate to the Foreign Intelligence Surveillance Court. The court, which meets in secret to hear government requests to carry out wiretaps and other surveillance in the United States, now hears only from the government.

Intelligence expert Richard Clarke recommends more technical support and resources for FISA court staff to prevent further objections to NSA information gathering activities. (AP)

Bates said a public-interest advocate would not be in the court’s interest.

“The participation of a privacy advocate is unnecessary — and could prove counterproductive — in the vast majority of [court] matters, which . . . typically implicate the privacy interests of few persons other than the specified target,” wrote Bates, who said he was representing the views of current and former judges on the FISC as well as on the panel that hears any appeals of its rulings.

Bates said an independent advocate appointed at the discretion of the courts “is likely to be helpful,” whereas a standing advocate with authority to intervene at will could hamper the court’s work.

Asked about that point at the Senate hearing, Cass Sunstein, a member of the White House review group, responded: “We respectfully disagree.” He added that the advocate would likely participate in only a small number of cases that involve novel or difficult legal issues. “If there is a privacy or civil liberties concern, it is good to have someone who is specially authorized to take account of that concern in deciding whether to participate,” he said.

The review group also proposed that national security letters be issued only by the surveillance court when there are “reasonable grounds to believe” that the data sought are relevant to an authorized terrorism or espionage investigation. Currently, the letters may be issued by senior FBI officials in field offices. The FBI issues more than 20,000 of the letters each year for data such as phone subscriber information and telephone toll records, as well as banking and credit-card records. The data do not include phone-call content, which would require a court-approved warrant.

Bates said in his letter that requiring the court to authorize the letters would increase its workload dramatically. He expressed skepticism that the review group’s suggestion of expanding the number of surveillance court judges was workable.

“The sheer volume of new cases . . . would transform the FISC from an institution that is primarily focused on a relatively small number of cases that involve the most intrusive or expansive forms of intelligence collection to one primarily engaged in processing a much larger number of more routine, subpoena-type cases,” he wrote.

Read the report A report from the five-member Review Group on Intelligence and Communications Technologies contains 40-plus recommendations on the NSA. Read it.

The judges also opposed ending the NSA’s bulk collection of phone records — which does not include call content — because, they said, it likely would result in “many more” applications to the court to obtain the data on a case-by-case basis. Today, the NSA compels phone companies to turn over all call records every day and gathers them in a massive database.

Obama is considering the review group’s recommendation to shift that database away from government control and have the phone companies hold the data instead. The group recommended that the NSA have access to the data only with court approval for each number it wants to query.

“Any of these variations would impose significant new burdens on the FISC,” Bates wrote.

At the Senate hearing, there was much discussion about the effectiveness of the phone-

records collection. Review group members stood by the statement in their report that the collection “was not essential to preventing attacks,” but clarified that that did not mean it could not be useful in the future.

They stressed that the program’s utility did not drive their recommendation to shift control of the database. “Our primary concern . . . [was] the risk [that] somewhere down the road someone will figure out how to and want to misuse the data,” group member Geoffrey R. Stone said. Taking the database out of government hands does not eliminate the risk, he said, “but reduces the potential for the data to be abused.”