Last week, Senate Democrats agreed to strip language from the bill that would have granted bargaining rights to TSA screeners. Senate Republicans had requested assurances that the measure would not grant screeners such rights, largely because President Bush has threatened to veto the bill, citing the TSA provision.

"We don't see it as an issue to national security that TSA workers have the right to bargain," Thompson said. He added, however, that conferees view the TSA issue with reluctance, especially if its inclusion means the entire bill would falter. He said there has been some discussion with the Senate as to whether there is another way to get at the collective bargaining issue.