An effort to shore up the nation's port security cleared a House committee Wednesday after Republicans beat back a Democratic attempt to screen all cargo for radioactive material.

Lawmakers once united in opposition to a proposed U.S. ports deal with Dubai sparred at the hearing over Democrats' demands for 100 percent radiation screening of shipping containers.

The bill, headed for a vote on the House floor next week, would require the Homeland Security Department to give a timetable for placing radiation portal monitors at U.S. seaports that don't already have them, and assess the security implications of screening programs for foreign ports.

Reps. Dan Lungren, R-Calif., and Jane Harman, D-Calif., sponsored the broad port security measure last month as Congress was in an uproar over now-abandoned plans by DP World to manage terminals at ports in New Jersey, New York, Baltimore, New Orleans, Miami and Philadelphia.

The panel rejected along party lines an amendment offered by Rep. Edward Markey, D-Mass., which would require within five years radiation screening for every container coming into the U.S.

Republicans said the deadline was unrealistic and the scanner technology is still too faulty to deploy through a mammoth port system that handles 20,000 cargo containers every day.

At that, some Democrats erupted.

Rep. Peter DeFazio, D-Ore., slammed his fist as he called current port security programs "a joke."

"We have a faith-based honor system. People could ship a nuclear bomb here today," he said, accusing GOP leaders of buckling to pressure from business groups that oppose greater regulation.

Republicans denied any influence from lobbyists.

"Somebody said we're lackeys for the industry. I'm not a lackey for anybody," said Lungren.

Committee chairman Peter King urged both sides to cut back partisan accusations.

"Any implication that anyone on either side of the aisle is not concerned about homeland security, is not concerned about the loss of human life, it demeans and cheapens the debate," said King, R-N.Y.