Aviation Consumer Action Project head Paul Hudson told USA Today that he is now opposed to the so-called Passenger Bill of Rights.
"This would seem to give a green light legalizing very long airline confinements," Hudson said.
An earlier version of the bill would have required airlines to release passengers kept on the runway for more than three hours. But the newspaper reported that the new bill exempts airlines that have filed a plan for ground delays with the U.S. Department of Transportation.
Airlines need "flexibility to operate under their own plans for addressing extreme weather delays without compromising passenger safety or creating further inconvenience," David Castelveter, spokesman for the Air Transport Association, told USA Today.
The legislation was proposed after JetBlue and American Airlines kept passengers on the tarmac for several hours during bad weather.