Two Democratic senators want airlines to eliminate any expiration dates associated with travel credits that were issued to customers for pandemic-related reasons.

Sens. Ed Markey of Massachusetts and Richard Blumenthal of Connecticut, both members of the chamber’s Committee on Commerce, Science, and Transportation, told airliners on Monday in a series of letters that they should offer cash refunds for pandemic-related cancellations and urged the companies to make all pandemic-related flight credits valid indefinitely “at a minimum.”