A fee charged to airline travelers to help pay for airport security would more than double under President Bush's spending proposal for the Homeland Security Department (search).

Bush's plan calls for boosting the security fee from $2.50 to $5.50 for a one-way airline ticket and from a maximum of $5 to $8 for multiple legs. The hikes are expected to generate $1.5 billion.

Debby McElroy, president of the Regional Airline Association (search), criticized the proposal as taxing an industry that already carries one of the highest tax burdens.

"This could put further pressure on airline revenues at a time when many carriers are struggling for their very survival," McElroy said.

James C. May, president and CEO of the Air Transport Association (search), said the proposal "demonstrates a complete failure to comprehend the economics of a crippled industry."

Homeland Security Department spokesman Brian Roehrkasse declined comment before the budget is released. "We are confident that it will contain the resources we need to continue to do our job," he said.

Bush plans to submit his budget proposal to Congress on Feb. 7. Portions of the Homeland Security budget were obtained Thursday by The Associated Press.

The White House wants to spend $41 billion on the agency in fiscal year 2006, which begins Oct. 1. That's nearly the same amount as the current year. However, the department would see a 7 percent increase in money earmarked for specific security programs, from $32 billion to $34.2 billion.

The Bush plan calls for $100 million to be spent in the next two years for new equipment to detect explosives on airline passengers. Most U.S. airline passengers aren't screened for explosives before boarding a plane. The commission that investigated the Sept. 11 attacks called that a vulnerability that Congress must address.

Another budget provision would set aside $174 million to complete installation of high-speed computer connections to replace dial-up connections used by about half of the nation's airports.

Officials of the Transportation Security Administration have said the upgrade is needed because some of the nation's largest airports do not have telephone or computer connections among administrative, screening and baggage areas. That poses a security risk because a problem could occur in one area of an airport and another area may not learn of it right away.

The spending proposal also calls for creating an office to coordinate programs that collect information about foreign visitors, airline and ship crews, and hazardous materials workers.

The plan would provide more money for authorities to crack down on undocumented workers and arrest and deport illegal immigrants, but it would fund only 210 more Border Patrol agents. A bill signed by Bush last year called for 2,000 additional agents.

Customs and Border Protection would get $125 million to buy equipment to detect radioactive materials in trucks, trains, cars, air freight, packages and people, including a new generation of monitors that detect gamma and neutron radiation.

A new Domestic Nuclear Detection Office would develop a system that tracks attempts to bring nuclear or radioactive materials into the country or to assemble them for illegal use.

At a Senate hearing Wednesday, Connecticut Sen. Joe Lieberman, top Democrat on the Homeland Security Committee, said programs to secure U.S. borders, ports and rail systems were underfunded.

But Senate Commerce Committee Chairman Ted Stevens, R-Alaska, told department officials it was unlikely they would receive more money. "I would urge a review of your situation as to how to get the job done better with the money that's there now," he said.

Meanwhile, four unions filed suit Thursday to block new Department of Homeland Security regulations limiting collective bargaining rights of tens of thousands of the agency's 180,000 employees. The regulations replace salaries based on workers' seniority with a merit pay system and give managers broad authority to change employees' shifts and duties without notice.

The lawsuit was filed in U.S. District Court in Washington. The unions bringing the lawsuit were the National Treasury Employees Union, American Federation of Government Employees, National Federation of Federal Employees and National Association of Agriculture Employees.