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. …

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.