Major U.S. air carriers are warning that the country’s “commerce will grind to a halt” if Verizon and AT&T go ahead with plans to deploy their new 5G mobile internet technology on Wednesday.

The airlines say the new technology will interfere with safe flight operations. 

The dispute between two major segments of the U.S. economy has been waged for months in Washington regulatory agencies, with the airline industry contending that the mobile carriers’ technology upgrade could disrupt global passenger service and cargo shipping, while the mobile carriers claim the airlines failed to upgrade equipment on their aircraft to prevent flight problems.

The new high-speed 5G mobile service uses a segment of the radio spectrum that is close to that used by altimeters — devices in cockpits that measure the height of aircraft above the ground. 

AT&T and Verizon argue that their equipment will not interfere with aircraft electronics and that the technology is being safely used in many other countries. 

In a letter Monday to Transportation Secretary Pete Buttigieg, chief executives at Delta Air Lines, American Airlines, United Airlines and seven other passenger and cargo carriers protested the mobile carriers’ plan to roll out their upgraded service on Wednesday. 

While the Federal Aviation Administration previously said it would not object to deployment of the 5G technology because the mobile carriers said they would address safety concerns, the airline executives said aircraft manufacturers have subsequently warned them that the Verizon and AT&T measures were not sufficient to allay safety concerns.

The mobile companies said they would reduce power at 5G transmitters near airports, but the airlines have asked that the 5G technology not be activated within 3.2 kilometers of 50 major airports. 

The airline executives contended that if the 5G technology is used, “Multiple modern safety systems on aircraft will be deemed unusable. Airplane manufacturers have informed us that there are huge swaths of the operating fleet that may need to be indefinitely grounded.” 

The airline industry executives argued that “immediate intervention is needed to avoid significant operational disruption to air passengers, shippers, supply chain and delivery of needed medical supplies.” 

After the airlines’ latest protests, AT&T said Tuesday it would postpone its new wireless service near some airports but did not say at how many or where. Verizon had no immediate comment. 

In a statement Monday, the FAA said it “will continue to keep the traveling public safe as wireless companies deploy 5G” and “continues to work with the aviation industry and wireless companies to try and limit 5G-related flight delays and cancellations.” 

The White House said Tuesday that the Biden administration is continuing discussions with the airline and telecommunications companies about the dispute.

Some material in this report came from The Associated Press.