President Bush has threatened to delay a six-day tour of Africa in order to stay in Washington and push through a controversial wiretapping law that is set to expire later today.

In a high-stakes showdown with Congress, Mr Bush has also promised to veto a Bill to outlaw waterboarding, the simulated drowning technique widely classed as torture.

Mr Bush warned the Democratic-led House of Representatives yesterday that he was ready to delay his trip to Africa today to ensure the wiretapping Bill, which he sees as crucial to the battle against terrorism, passes the lower chamber.

Congress last year passed legislation temporarily authorising warrantless wiretaps after it emerged that the Mr Bush had, in reaction to the 9/11 attacks, authorised the National Security Agency to eavesdrop, without court warrants, on calls and e-mails between the United States and abroad in cases deemed to have a terror link.

That authorisation expires today but House Democrats have refused to rubber-stamp a version of the Bill that passed the Senate on Tuesday and would both make the law permanent and provide legal immunity to telecoms firms who assist in the wiretaps - which critics say contravene US privacy laws.

“The lives of countless Americans depend on our ability to monitor terrorist communications,” Mr Bush said in a news conference. “Our intelligence professionals are working day and night to keep us safe, and they’re waiting to see whether Congress will give them the tools they need to succeed or tie their hands by failing to act."

House Democrats are opposed to a provision for blanket immunity to telecoms firms facing lawsuits for co-operating in the wiretapping program.

On Wednesday, the House failed to agree on another temporary extension to the law while a compromise is found and yesterday Democrats ramped up their defiance as the House voted to hold two of Mr Bush's confidants in contempt for ignoring subpoenas to testify to a committee about a scandal regarding the firing of prosecutors in 2006.

The move angered Republicans, who walked out of the chamber in protest and boycotted the vote. “We will not stand here and watch this floor be abused for pure political grandstanding at the expense of our national security,” John Boehner, the House Minority Leader, said as he led his peers out of the chamber.

The House voted 223-32 to hold the White House chief of staff Joshua Bolten and former Bush legal adviser Harriet Miers in contempt of Congress, a move quickly denounced by the Administration as a waste of time.

“The Justice Department will not ask the United States Attorney to follow through on the contempt charges,” a White House spokeswoman said.

The Senate Majority Leader Harry Reid sent a letter to Mr Bush yesterday warning the President that he would be responsible if the wiretap law expired.

“I regret your reckless attempt to manufacture a crisis over the reauthorization of foreign surveillance laws,” Mr Reid wrote, insisting that intelligence services still could carry out their work without the law.

“Instead of needlessly frightening the country, you should work with Congress in a calm, constructive way to provide our intelligence professionals with all needed tools while respecting the privacy of law-abiding Americans,” he said.

Mr Bush's trip to Africa – one region of the world where the United States is well seen – will take him to Benin, Tanzania, Rwanda, Ghana and Liberia, all countries that have been seen huge US aid flows, especially for tackling Aids/HIV.

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