Congressional hearings on President Obama’s fiscal 2011 budget request will dominate homeland security discussions on Capitol Hill this week, with full-body scanners, terrorist trials and firefighter grants likely to top the list of talked-about items.

Money for full-body scanners at airports would increase under the administration’s request, as would funding for air marshals on commercial jets — both prompted by the attempted Christmas bombing of a jetliner in Detroit.

The proposed budget also would include $200 million for security at U.S. terrorism trials, but it would decrease firefighter grants by nearly 25 percent in fiscal 2011, to $610 million. The administration’s original plan to try Guantanamo Bay detainees and other terror suspects in federal courts has raised sharp criticism from House and Senate Republicans, as well as some Democrats. Meanwhile, proposed grant reductions have become annual fodder for bipartisan criticism from members who want the money for their districts.

Leaders on the authorization and appropriations committees have expressed disapproval of the proposed grant reductions — something they might bring up again this week as Homeland Security Secretary Janet Napolitano appears before them to testify about the budget request.

“These cuts will hurt our state and local partners most and come at a time when communities are hard-pressed to find this critical funding on their own,” said Homeland Security Committee Chairman Joseph I. Lieberman, I-Conn.

Obama’s plan calls for a 2 percent increase in the Department of Homeland Security’s discretionary budget, which would amount to roughly level funding, bringing the total request to $43.6 billion.

Of that money, $215 million would be used to buy and set up 500 “advanced imaging technology” machines at airports, bringing the total number of whole-body scanners in the deployment pipeline to 1,000. Another $519 million would go toward hiring machine operators and purchasing additional baggage-screening equipment.

Whole-body imaging machines can “see” through clothing to generate revealing images of travelers’ bodies — and anything they are concealing — and supporters believe the machines might have caught the bomb materials allegedly smuggled onto Northwest Airlines flight 253 by suspected terrorist Umar Farouk Abdulmutallab on Dec. 25.

The ability of the machines to take semi-nude images of travelers has raised criticisms from privacy advocates in Congress, who argue the machines should not be used as the first line of screening at airports. In response, manufacturers created ways to blur the faces of travelers to conceal their identities, and are working on “automated detection” software that would reduce user images to a simple outline.

In addition, although the administration is asking for money for 300 cargo, airport and border-screening employees, its request would also reduce the number of some Border Patrol and Coast Guard personnel.

The top Republican on the Homeland Security Appropriations Subcommittee, Kentucky Rep. Harold Rogers, called the proposed reductions of 180 border officers and 1,100 Coast Guard “indefensible.” DHS officials have said the reduction in Coast Guard staff was planned as part of its fleet revitalization effort, and the Border Patrol has become efficient enough that losing some staff by attrition would not hurt its operational capabilities.

Money for the high-tech Secure Border Initiative, which uses fencing, intelligence and surveillance equipment to control the U.S.-Mexico boarder, would be cut by $226 million, bringing the fiscal 2011 total to $574 million. Administration officials said the proposed reduction reflects uncertainty about the program, which has suffered delays.

Meanwhile, Obama’s budget request would eliminate a number of departmental projects. In addition to the proposed reduction to firefighter grants, the request also would eliminate all grant money for emergency operations centers, a program that Obama tried unsuccessfully to cut in fiscal 2010 only to see Congress increase the program’s funding to $60 million. The administration has argued the program doesn’t award grant money based on risk and has said other grant programs are more effective.

The administration’s request would also eliminate a terrorism insurance subsidy the Treasury Department provides insurers, which the White House termed “an excessive federal subsidy.” Created in 2002 to offset catastrophic losses in the insurance industry, the Terrorism Risk Insurance Program would cost $147 million in fiscal 2011 and $320 million in fiscal 2014, its sunset date.

The Senate Homeland Security and Governmental Affairs Committee will hold its budget hearing at 10 a.m. Wednesday in 342 Dirksen. The House Homeland Security Appropriations Subcommittee will have its hearing at 10 a.m. Thursday in 2359 Rayburn. At 2 p.m. the same day, the House Homeland Security Committee will hold its hearing in 311 Cannon.