U.S. spy chiefs joined ranks on Wednesday against efforts in Congress to sharply curtail the National Security Agency's vast data collection program, warning that would endanger an essential intelligence tool.
In an unusually public discourse on a secret spying program, James Clapper, the director of national intelligence, joined the White House and senior Republican lawmakers who oversee the intelligence agencies in cautioning against cutting funding for NSA's data collection.
Clapper, in a statement, urged an "open and candid discussion" about foreign surveillance efforts and "careful consideration of the potential effect of limiting the intelligence community's capabilities" under the current law.
Intelligence officials are worried about a proposed amendment to the defense appropriations bill in the House of Representatives which would end the NSA's broad authority to collect a vast number of communications records, including records on telephone calls.
The House was expected to consider it on Wednesday.
The measure proposed by Representative Justin Amash, a Tea Party-backed conservative Republican, is the first such move since former NSA contractor Edward Snowden leaked details of surveillance programs that collect and store huge volumes of electronic communications like phone call records and emails.
Amash has expressed confidence the amendment will pass. Will Adams, a spokesman for the Michigan congressman, said, "We are optimistic that we will have the votes to get it across the finish line."
Clapper's statement came amid a push against the proposal by the White House and other senior intelligence officials, including Army General Keith Alexander, the head of the NSA, who visited lawmakers on Capitol Hill on Tuesday to warn about the implications of the amendment.
White House spokesman Jay Carney said in a statement late on Tuesday that Obama welcomed a debate on safeguarding privacy, but opposed Amash's amendment, saying it would "hastily dismantle one of our intelligence community's counterterrorism tools."
Senior House Republicans, including Intelligence Committee Chairman Mike Rogers and Armed Services Committee Chairman Buck McKeon, circulated a letter to colleagues urging them to oppose the amendment.
"While many members have legitimate questions about the NSA metadata program, including whether there are sufficient protections for Americans' civil liberties, eliminating this program altogether without careful deliberation would not reflect our duty ... to provide for the common defense," they said.