WASHINGTON, Feb 13 (Reuters) - U.S. President George W. Bush on Wednesday said he would oppose another temporary extension of a law empowering U.S. spy agencies to track communications of terrorism suspects without a court order and pressed Congress for a long-term fix.

The Senate on Tuesday approved legislation that would enshrine into law the surveillance powers and grant retroactive immunity to telephone companies that took part in the Bush administration's warrantless wiretapping program.

"It's time for Congress to ensure the flow of vital intelligence is not disrupted," Bush told reporters in the Oval Office on Wednesday. "It is time for Congress to pass a law that provides a long-term foundation to protect our country and they must do so immediately."

However, Democrats in the U.S. House of Representatives, who have opposed immunity for the phone companies, could vote on another proposed extension, this one for 21 days, on Wednesday, a top congressional aide said on Tuesday.

"The time for debate is over," Bush said. "I will not accept any temporary extension."

He warned that enemies of the United States were already plotting new attacks that would dwarf the Sept. 11 attacks, however Democrats in Congress have insisted on better protections for Americans' civil liberties.

In the Senate measure, lawmakers did bolster the protection of privacy rights of law-abiding Americans swept up in the hunt for suspected terrorists.

The White House and Democratic-led Congress have been wrangling for months over whether to make permanent a program that allowed surveillance of communications between people in the United States and others overseas if one had suspected terrorist ties.

Another key concern has been some 40 civil lawsuits filed accusing AT&T Inc., Verizon Communications Inc. and Sprint Nextel Corp. of violating Americans' privacy rights in helping the warrantless domestic spying program that started shortly after the Sept. 11 attacks.

"If these companies are subjected to lawsuits that could cost them billions of dollars, they won't participate, they won't help us, they won't help protect America," Bush said.

(Reporting by Jeremy Pelofsky and Matt Spetalnick, editing by Vicki Allen)

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