A last-minute addition to the proposed US Department of Homeland Security Bill will allow the government to punish malicious computer attackers with life imprisonment.

During closed-door negotiations, the House of Representatives' Republican leadership inserted the 16-page Cyber Security Enhancement Act (CSEA) into the Bill, which has been approved by the House in a 299 to 121 vote.

CSEA allows law enforcement officers to carry out internet or telephone eavesdropping without first obtaining a court order. It also demands life sentences for hackers who "recklessly" endanger lives.

In addition, the Bill allows commercial airline pilots to carry guns in cockpits and gives airports a one-year delay in the 31 December deadline to install explosive detection systems to screen all checked baggage.

"Defending against terrorists who can strike any time with any method requires a change in our approach to the problem," said Lamar Smith, the Republican sponsor of the Bill, in a statement.

But civil liberties groups, such as the Electronic Privacy Information Centre (Epic), have objected to portions of CSEA.

Epic director Marc Rotenberg said the revised Homeland Security Bill now before the Senate contained an exemption to the Freedom of Information Act (FOIA) for "Critical Infrastructure Information".

This provision would allow federal agencies to withhold agency records that would otherwise be available under the FOIA, he said.

And John Sweeney, president of the American Federation of Labour-Congress of Industrial Organisations, called the bill a shameful and unprecedented assault on workers.

President Bush said he was pleased with the House vote.