Maryland Gov. Harry Hughes, in a letter delivered to the National Governors Association, said yesterday that Congress should rescind laws enacted last year that make it harder for states to qualify for federal unemployment benefits.

"I submit that this is no longer a Maryland problem. I see no encouraging signs that our economy will recover in the immediate future," Hughes said in a letter to Gov. James B. Hunt of North Carolina, chairman of the NGA human resources committee. Hughes urged the governors to develop unemployment policies to cope with the cutoff of federal funds that has or will soon affect 15 states, including Maryland.

Hughes convened a special session of the Maryland General Assembly last Friday that approved emergency legislation to allow the state to pick up the cost of benefits for some 11,000 Marylanders who lost their federal unemployment checks on Aug. 1. Throughout the week Hughes and his Human Resources Secretary, Kalman R. Hettleman, criticized the Reagan administration for proposing federal regulations that disqualified thousands of long-term jobless from federal benefits.

Hughes' letter to the governors, mailed last week but released yesterday, demonstrated his interest in keeping the unemployment issue alive as the Sept. 14 primary election approaches.

Hughes is not attending the governor's conference in Oklahoma this week because of the special session and a tight campaign schedule, according to his spokesman, Lou Panos.