Nine U.S. Senate Democrats led by Edward Markey and Elizabeth Warren of Massachusetts and Richard Blumenthal of Connecticut on Tuesday sent a letter to each of the country’s major airlines urging them to issue full cash refunds to all customers who cancel flights during the Covid-19 crisis and to all U.S. citizens who encounter flight cancellations while stranded in countries that implemented travel restrictions. Although most U.S. airlines have taken some steps to temporarily waive coronavirus-related change and cancellation fees, travelers who cancel their flights largely have received vouchers rather than cash refunds.

“The ongoing pandemic is placing enormous financial strain on millions of Americans, and families need cash to pay for essentials such as food, housing, and medical care,” wrote the Senators. “In light of this pressing need and the unprecedented bailout—to the tune of $25 billion—that the airline industry just received from Congress, we believe your company has a moral responsibility to provide real refunds, not travel vouchers, to consumers, and to support State Department efforts to repatriate any American citizens trying to come home.”

In the letter, the lawmakers asked each airline to estimate the total value of all travel vouchers and credits issued during the pandemic and the number of flights canceled, including flights canceled due to travel restrictions. It also asked for a commitment from each airline to issue full cash refunds for travelers who either experience flight cancelations due to travel restrictions or who voluntarily canceled flights during the outbreak, including refunds in lieu of travel credits to those who have already received but not used their credits, Finally, it called on the airlines to work with the State Department to “expedite” commercial flights “at an affordable price” for all U.S citizens stranded abroad.

The call from the U.S. Senators comes on the same day the International Air Transport Association issued a plea to governments around the world to allow airlines to provide vouchers for canceled flights rather than direct refunds as a way to help mitigate their liquidity crisis. Some governments, such as Canada and Brazil, have already done so, said IATA director general Alexandre de Juniac, who, while acknowledging the hardship to customers, called the situation a “matter of survival” for the airlines.