Professional meeting planners are watching closely as a proposal to ban laptop computers on commercial airline flights from Europe takes shape. One industry association spokesperson estimated laptop restrictions could cost business travelers $655 million a year in lost productivity.

It’s been widely speculated that the U.S. Department of Homeland Security (DHS) intends to implement the ban on personal electronic devices (PEDs) on flights from Europe and the United Kingdom to the United States. Such a ban would severely curtail the ability of business travelers to review computer files and complete business-related tasks while flying.

Representatives from the DHS met today with European Union officials to discuss the ban on laptops and other large PEDs.

Air transport and business trade association executives are voicing concerns about the proposed ban, which comes on the heels of similar PED restrictions on certain flights to the United States and United Kingdom from cities in the Middle East and North Africa implemented nearly two months ago.

“Businesses will cancel trips rather than risk having laptops checked due to risk of confidential information,” wrote Alexandre de Juniac, director general of International Air Transport Association (IATA), in a letter to DHS Secretary John Kelly.

IATA members have expressed serious concerns that any expansion of the ban on PEDs in the aircraft cabin will result in a negative impact on airline passengers, commercial aviation and the global economy, de Juniac warned the DHS secretary.

Estimating an annual loss of more than one billion dollars in costs to passengers burdened by the ban, de Juniac implored DHS officials and the Trump administration to consider alternatives to restricting business travelers from using their laptops in cabins on flights from Europe to the United States.

Alternative measures suggested by the IATA include random explosive trace-detection checks of PEDs at airport carry-on luggage lines, as well as visual inspections by airport security personnel if a laptop or any other PED looks suspicious, such as showing evidence of tampering with the battery compartment.

The U.S. Travel Association, which vocally opposed the DHS ban on large PEDs from flights to the United States coming from the Middle East and North Africa, estimates European travelers spend an average of $3,500 per visit to the United States, according to The Hill. The D.C.-based publication pointed out that 60 to 90 percent of all travelers use PEDs on flights from Europe.

With business travelers comprising the lion’s share of profits for airlines flying into the United States, banning the use of laptops in cabins could have severe financial consequences to airlines, hotels and the tourism industry.