A senior U.S. senator on Tuesday called for an end to the National Security Agency’s phone records collection program, arguing that it treads too heavily on Americans’ privacy rights without having proved its value as a counterterrorism tool.

In a speech at Georgetown Law’s Center on National Security and the Law, Senate Judiciary Committee Chairman Patrick J. Leahy (D-Vt.) said he has introduced bipartisan legislation that would stop the controversial program, which allows the NSA to amass a database of Americans’ call logs. He said he is working on a bill to address concerns about a separate program that collects the e-mails and phone calls of foreigners overseas, including their communications with Americans.

The measure he introduced, he said, would allow a more limited form of phone records collection under the Foreign Intelligence Surveillance Act, which is the subject of intense public debate in light of revelations by former NSA contractor Edward Snowden.

“Congress did not enact FISA to give [the government] dragnet surveillance powers to sweep in the data of countless innocent Americans,” said Leahy, who noted that his first vote as a senator in 1975 was in favor of creating the Church Committee, which investigated intelligence agency abuses, including spying on civil rights leaders.

Leahy’s bill is among a number of proposals to reform FISA following Snowden’s disclosures, which together with lawsuits by privacy groups sparked the release of formerly classified court opinions and other documents.

The Senate Intelligence Committee will hold a public hearing Thursday to examine some of the proposals. Leahy’s panel will hold a public hearing next Wednesday to do the same.

The committees will hear from Director of National Intelligence James R. Clapper Jr. and NSA Director Keith Alexander. Along with other U.S. officials, they have insisted that the programs have been repeatedly found to be constitutional and that Congress was briefed on the programs before reauthorizing the statutes underlying them.

Some lawmakers have said they didn’t know that they were approving the bulk records collection when they voted in 2011 to reauthorize the underlying FISA provision. Others have said they support current NSA programs. The phone records program began shortly after the attacks of Sept. 11, 2001, under an assertion of executive branch authority. It was put under FISA court oversight in 2006.

Senate Intelligence Committee Chairman Dianne Feinstein (D-Calif.) does not support ending the phone records collection. “It would remove an important and effective intelligence tool and one that has been repeatedly determined to be lawful,” a committee aide said.

Feinstein, however, is working on legislation that would increase transparency and privacy protections. She has outlined some changes she would consider, including reducing the length of time the NSA can keep the phone records from five years to two or three.

Other proposals raised by lawmakers or policy experts include having the phone companies or a third party retain the data instead of the NSA. Companies are averse to that idea, fearing that they will be subject to an avalanche of requests from civil litigants, local law enforcement and others seeking access to the trove.

Other proposals focus on the FISA court, which meets in secret and hears only the government’s case for surveillance. Some lawmakers have proposed having a public advocate who could tell the judge how the government’s proposal would affect Americans’ privacy rights.

The House in July nearly approved a measure to end the bulk records collection. Some analysts say it is unclear whether Leahy’s bill would end bulk collection, given the FISA court’s apparent willingness, as shown in a recently released opinion, to interpret the underlying law expansively.

Leahy, Sen. Charles E. Grassley (R-Iowa) and seven other Judiciary Committee members called on the intelligence community inspector general on Monday to review the government’s use of FISA and USA Patriot Act surveillance authorities, and to make his findings public.