(CNN) Would-be air travelers hold billions of dollars in credits for future flights, and two US senators want airlines to drop restrictions like expiration dates -- or to refund the customers in cash. Ed Markey and Richard Blumenthal, both Democrats, are sending a letter to 10 US airlines Monday asking the carriers "commit to providing a cash refund for all tickets that are canceled during the coronavirus pandemic." Congress extended more more than $50 billion in taxpayer dollars to the airlines over the past year to fund payroll expenses, and some airlines took government loans for other costs. Refunds quickly became the most griped about part of air travel during the pandemic, according to the Department of Transportation. Passengers filed more than 107,000 official complaints since March 2020, and 95,000 of those -- 89 percent -- are about refunds, DOT data show.

Source: CNN May 10, 2021 12:22 UTC