Maryland Gov. Harry Hughes is considering an emergency session of the legislature and will meet today with the state's congressional delegation to find a way to help 10,000 Marylanders scheduled to lose their federal unemployment checks on Saturday.

Today's meeting and the possibility of a special session were sparked by the discovery last week that new federal guidelines will cost Maryland more than $5 million a month in extended benefits for people who have been out of work for more than 26 weeks.

State officials have known for a year that federal unemployment benefits would be reduced, and last winter the legislature authorized the state to make up for any federal cutbacks in this program. However, state officials had not expected the federal cuts to occur this soon, and had set a Sept. 26 date to begin state involvement.

Hughes, a Democrat who is seeking reelection this year, has come under pressure from politically potent labor unions to convene an emergency legislative session to deal with the unexpected federal cutoff. The state has been reeling from unemployment that reached nearly 10 percent, the highest since before World War II. Unemployment in Maryland is now 8.6 percent.

Hughes spokesman Lou Panos said yesterday that the governor would convene an emergency session only if Congress is unwilling to consider an immediate reversal of the cuts. "Twenty states are in a position similar to Maryland and we're placing our first hope there in Congress ," Panos said.

Panos said that Hughes, a frequent critic of President Reagan, will meet with Maryland's representatives on Capitol Hill to gauge the potential for congressional action. After the meeting Hughes will confer with legislative leaders before moving ahead on a special session, Panos said.

Special sessions of the 188-member General Assembly, which normally convenes for three months in the winter, have occurred infrequently. State officials said yesterday that such gatherings could cost taxpayers as much as $15,000 a day. The last one was held in 1975 to enact several tax measures.

Because of the nearness of the September primary and November general elections, labor's call for immediate action by Hughes and the legislature was laden with political overtones.

Last week the state AFL-CIO met with three major gubernatorial candidates--Hughes, Democratic State Sen. Harry J. McGuirk and Republican Robert A. Pascal--to prepare an endorsement. But on learning of the impending unemployment benefits crisis, union officials announced they were withholding endorsements until they see how various candidates respond to their request for immediate action.

"We're not trying to blackmail anybody into holding a special session," said Thomas M. Bradley, president of the D.C.-Maryland AFL-CIO.

"We just didn't want to come out with an endorsement of anyone and then find them voting against us in a special session ."

Several labor sources said the group appeared to be leaning toward endorsing Hughes. However, they said that the group, which has money and workers to contribute to a campaign, had decided against making an endorsment before the September 14 primary. "We want to get all we can get from Hughes ," one union leader said. "Once you kiss an incumbent, it's goodbye."

Labor leaders said they urged a special session so that the state could rewrite its new law making it effective immediately and creating more flexible formulas.

State officials are concerned that a rewritten law that differs from federal guidelines could disqualify Maryland from receiving matching federal funds that comprise half the money paid out in extended unemployment benefits to Maryland job seekers..

Pascal yesterday came out in favor of a special session. Last week he released a letter to President Reagan calling the federal cutback "a mistake" that "short-sightedly failed to consider the enormous human cost." McGuirk said that if Congress does not solve the problem with immediate legislation the state should make up the payments, even if the new state law does not allow such action until Sept. 26.