(Adds details on IRS, no immediate comment from Treasury or IRS) WASHINGTON, March 8 (Reuters) - Top Democrats in the U.S. House of Representatives on Monday urged the Internal Revenue Service (IRS) to extend this year’s tax filing deadline until July 15. “We want to remind the IRS that many Americans continue to face the same health and economic challenges that necessitated an extension last year,” wrote the chairmen of the House’s Ways and Means Committee and the Oversight Subcommittee, referring to the filing delay in 2020 due to the coronavirus pandemic. Last year’s tax filing was extended by three months until July 15 because of the coronavirus pandemic. The IRS has extended the filing deadline for victims of Texas winter storms to June 15. Representative Richard Neal, the committee chair, and subcommittee chair Bill Pascrell said that as of the end of February, the number of returns filed was down by nearly 25% from last year at the same time, and the number of returns processed by the IRS was down 31%, while just 27% of telephone calls to the IRS are being answered. “Facing enormous strain and anxiety, taxpayers need flexibility now,” they wrote. “We demand that the IRS announce an extension as soon as possible.” The IRS and U.S. Treasury did not immediately comment. Last month, the National Association of Tax Professionals sought an extension to “significantly help preparers as they continue to wait for filing guidance as well as the many taxpayers who continue to experience health and economic challenges.” The IRS annually processes more than 150 million tax returns. As of the end of the 2020 filing season, the IRS processed over 100 million individual refunds totaling $276.1 billion, a 5.5% decrease in the number of refunds and 5.3% decrease in dollars refunded, the Government Accountability Office reported last week. The IRS generally pays interest on refunds paid later than 45 days after filing deadlines. In the 2020 tax year, the IRS paid $3.03 billion in interest, compared with $2.06 billion the prior year. (Reporting by David Shepardson in Washington Writing by Lisa Lambert Editing by Matthew Lewis)