Airline passengers who object to any type of physical screening are not going to fly anywhere, the head of the Transportation Security Administration told a congressional committee Tuesday.

Quizzed by lawmakers about a controversial new airport procedure that uses revealing full-body scan machines and intimate "pat-downs" of those who object or set off alarms, TSA Administrator John S. Pistole appealed to the flying public to become "partners" in the effort to combat terrorism.

But Pistole told the Senate Committee on Homeland Security and Governmental Affairs that his inspectors at 453 of the nation's airports are not going to back down in the face of complaints that techniques are invasive.

He said they try to strike a balance between privacy and security needs. "We want to be sensitive to people's feelings about privacy," he said. "We have to ensure that each person getting on every flight is secure."

Asked by Sen. John Ensign (R-Nev.) about groups that objected to all forms of search on religious grounds, Pistole was unambiguous: "While we respect that person's beliefs, that person's not going to get on an airplane."

A recent CBS poll found that 81 percent of those surveyed did not object to the screenings. Still, enough people have balked to fuel what is being called an "opt-out" day a day before Thanksgiving, one of the year's busiest travel days.

"This country needs security measures in place that not only keep us safe but also do not grossly violate privacy or constitute an unreasonable search, like the current protocol," National Opt-Out Day organizers said in a statement."Protest the federal government's desire to virtually strip us naked or submit to an 'enhanced pat down' that touches people's breasts and genitals in an aggressive manner."

The TSA is using 385 of the full-body scanners at 68 airports, with plans to increase the number to 500 by year's end and bring the total to more than 1,000 next year. Passengers selected at random go through the full-body scanners and are offered an "enhanced pat-down" as an alternative.