A key Senate panel voted Tuesday to extend a contested 2008 provision of foreign intelligence surveillance law that is set to expire at year’s end.

The vote is the first step toward what the Obama administration hopes will be a speedy renewal of an expanded authority under the Foreign Intelligence Surveillance Act to monitor the U.S. e-mails and phone calls of overseas targets in an effort to prevent international terrorist attacks on the country.

Director of National Intelligence James R. Clapper Jr. called the move by the Senate Select Committee on Intelligence “important” to the effort to ensure that authorities can identify terrorist operatives and thwart plots. Extending the provision is the intelligence community’s top legislative priority this year.

It is unclear, however, how quickly the full Congress will act to reauthorize the provision in the FISA Amendments Act of 2008, as the law is known. The committee’s vote was to extend it through June 2017.

The measure in question enables authorities to collect electronic communications in the United States without a specific warrant for each person as long as a surveillance court signs off on the targeting procedures as “reasonably designed” to ensure that those targeted are outside the United States.

Sens. Ron Wyden (D-Ore.) and Mark Udall (D-Colo.) opposed the extension on civil liberties grounds. Wyden, concerned that the provision allows innocent Americans’ e-mails and phone calls to be monitored without a warrant, has asked the administration to disclose how many Americans have had their communications monitored under the law.

“We have not gotten any clear answer on that,” said Jennifer Hoelzer, a Wyden spokeswoman. “Before the Senate passes any long-term extension, we need to know how many law-abiding Americans are having their communications reviewed with these authorities.”

The American Civil Liberties Union has filed a lawsuit challenging the 2008 law, arguing that it allows dragnet surveillance that could pick up Americans’ communications. But many current and former administration officials disagree, saying any collection of communications by Americans would be incidental and subject to procedures to shield their identities.

The ACLU is urging public hearings and more disclosure about the information the government is collecting before Congress votes on reauthorization.

In a joint statement, committee Chairman Dianne Feinstein (D-Calif.) and ranking Republican Saxby Chambliss (Ga.) said the law’s provisions have provided necessary intelligence to fight terrorism and understand adversaries’ intentions around the world. “These authorities cannot be allowed to expire, and we urge quick action by the Senate and the House,” they said.

For the most part, lawmakers have shown little desire to reopen the contentious debate of 2006-08, in which civil liberties advocates decried what they saw as a government sanction of wiretapping Americans without a court order, while proponents warned that failure to grant the government broader authorities could lead to another major terrorist attack on U.S. soil.

The law that passed at the time also established that targeting Americans overseas requires a warrant. The committee’s vote Tuesday extended that provision until mid-2017.

Left unchanged is the requirement for a court order to target Americans in the United States, which was mandated by the Foreign Intelligence Act of 1978, the law amended in 2008.