As part of the increasing brinkmanship between Bush's Republicans and the Democratic-controlled Congress, the Senate passed a bill that makes the law permanent, but House Democrats refused to rubber-stamp the measure.

"The Senate passed a good bipartisan bill to make sure our intelligence community has the tools to protect us from this real threat," Bush said after meeting with Vice President Dick Cheney, intelligence officials and Republican lawmakers.

"There's still an enemy which would like to do us harm," he said. "We've got to give our professionals the tools they need to be able to figure out what the enemy is up to so that we can stop it."

Democratic House Speaker Nancy Pelosi, concerned about possible infringement of US privacy laws and the bill's blanket immunity for companies that engage in the surveillance, accused Bush of fear-mongering and trying to bully lawmakers.

"The president knows full well that he has all the authority he needs to protect the American people," Pelosi said Thursday before Congress went on recess due to Monday's President's Day holiday.

"President Bush tells the American people that he has nothing to offer but fear, and I'm afraid that his fear-mongering of this bill is not constructive."

In a bid to raise the stakes, Bush threatened to postpone a trip to Africa in order to urge the passage of the legislation.

White House spokesman Scott Stanzel said Bush "wouldn't have said it if he wasn't prepared to delay his trip" but that he went ahead with the travel plans anyway "because the House has made it clear that they don't intend to act."

Before leaving, Bush criticized House lawmakers for going on a 12-day vacation without passing the bill, and urged the House to "get a good bill to my desk, which is the Senate bill, as soon as possible."

The two sides have clashed over the issue of immunity for telecom operators.

"Clearly the problem here is a majority of the Democrats in the House would rather see companies in court than they would terrorists in jail," Republican Senator Mitch McConnell told reporters after speaking with Bush.

Director of National Intelligence Mike McConnell has argued that the Foreign Intelligence Surveillance Act (FISA), which has been around for 30 years, needs modernization to keep up with advances in technology.

"For almost two years, we have worked with Congress to modernize FISA and ensure that the intelligence community can effectively collect the information needed to protect our country from attack -- a goal that requires the willing cooperation of the private sector," he wrote in The Washington Post.

"Without long-term legislation that includes liability protection, we will be delayed in gathering -- or may simply miss -- intelligence needed to protect the nation."

But Democratic Senator Edward Kennedy dismissed the notion that businesses require immunity in order to cooperate.

"This is sheer nonsense. Under FISA, companies already have absolute immunity for any lawful cooperation. Future companies will be deterred only from cooperating with illegal surveillance requests, which is the whole point of the law."

Stanzel told reporters that the lapse of the law did not mean that surveillance efforts would stop, only that attempts to start new efforts might become more lengthy and cumbersome.

"Some of the efforts that are currently underway have an opportunity to continue; new efforts would have to go through the old process," Stanzel said.