The FCC waived certain rules affecting LightSquared's network plans earlier this year, allowing the company to build a hybrid satellite and LTE (Long-Term Evolution) network as long as it tested for and solved interference with GPS (Global Positioning System).

Since then, members of the GPS industry and some lawmakers have attacked the plan and the FCC's waiver as hazardous to GPS.

On Thursday, the House Appropriations Committee passed a measure that would use Congress' control of the FCC's purse strings to stop the agency from letting LightSquared move forward.

"None of the funds made available in this Act may be used by the Federal Communications Commission to remove the conditions imposed on commercial terrestrial operations ... until the Commission has resolved concerns of potential widespread harmful interference," with GPS, said the text of the measure, an amendment to a funding bill.

The amendment came as LightSquared and the FCC came under sharp criticism at a separate Congressional hearing about the carrier's plan, in which it wants to operate a cellular network in frequencies close to those used by GPS devices. The company plans to operate its land-based network alongside a satellite system and sell services at wholesale to other carriers.