Gladys Noon Spellman leaned back in her chair and laughed heartily. "What percentage of the vote will I get?" she said, repeating a question. "Well, Edna won't settle for less than 99 percent. And she wants to get the names of the one percent we don't get."

It is safe to predict that Spellman, 60, seeking her third term in the House of Representatives, will not receive 99 percent of the vote and that her chief aide and alter ego Edna McLellan will not be able to learn the names of those who vote against her.

Although her Republican opponent for the seat from Maryland's 5th District, Saul J. Harris, is running an aggressive race, both polls and observers indicate that Spellman will get more than the "50 percent plus one vote," she says she sets as her goal in every campaign.

In fact, the Spellman-Harris race was summed up by one of Prince George's County politican in one sentence: "If there's one person on the East Coast who has a lock on her race, it's Gladys."

Not so, says Harris, who at 55 is making his first run at elective office, "Gladys can be beaten if the people take a good look at her record," he said "I think Prince George's is a very conservative community. She says she's running on her record. I say she's running on ther rhetoric."

Aside from the facts that they both live in the 5th District, are Jewish and claim to like one another, Spellman and Harris have virtually nothing in common.

Spellman's political career dates to the early 1960s, including a stint on the county commission and later county council and four years in Congress.

Harris has never run for office and got into this race only when he offered his services to the Republican Party and was told he could best serve by running for Congress.

"I may be a newcomer politically, but I've dealt with the Congress for 20 years and I understand it and I know a lot of people there," he said. "I would know my way around."

But Harris tries not to take himself too seriously. Asked on a television interview why he was trying to start his political career on the federal level, he quipped, "At my age, I don't have time to start anywhere else."

By all indications Harris is faced with a formidable test this race. Polls taken early this year showed Spellman second only to Acting Gov. Blair Lee III in name, recognition around the state and well in front of him in terms of approval from the voters.

In addition, she has developed an excellent reputation for constituant services, something she emphasizes whenever speaking to voters. Representing an area heavily populated with government workers, she has devoted much of her efforts on the Hill to such subjects as Civil Service retirement programs.

"We've worked hard at it and we're proud of the work we've done," Spellman said. "If people call us and need help with something we feel we owe it to them to try and help with their problems."

Spellman's most recent accomplishment in the area of constituent service was helping to save a post office in Brentwood that was to be raged. A number of senior citizens who use the post office sought help from Spellman, who helped to preserved it.

"I know, I know, I keep hearing all about Glady's and her great constituent services," Harris said. "She always brings it up whenever we're speaking at the same place.

"But that's her job, that's what she's supposed to do. I don't think a congressman should be applauded because she's doing her job."

Although Harris' rhetoric is inclined towards attacks on his opponent's record, he also espouses generally conservative positions on economic and defense issues, blasting President Carter's recntly announced plan to fight inflation as "talk and no substance."

But every time Harris mades a point against Carter in a recent press release, he tacks Spellman's name on behind the president's. Thus: "Under Carter and Spellman (the inflation rate) is now more than 10 per cent. While Carter and Spellman talk and talk and talk about inflation, the rate continues to climb."

Unlike the combative Harris, who has decided to attack his opponent forcefully to gain the recognition he needs, Spellman is running an extremely low-key campaign.

She has spent much of her time campaigning for County Executive Winfield M. Kelly Jr. who faces a tough reelection fight against Republican Lawrence J. Hogan. But she has had time to take a few shots at Harris.

"I'm not saying this to put him down," she said, "but I think he's formulated a lot of his ideas as he has gone along. He's still learning. He's made some mistakes in his literature, but I don't think they're intentional. He just didn't know.

"For example, his literature is mistaken when it says I 'voted for the Panama Canal treaties,'" she said, "because the House didn't even vote on that treaty. How could I vote against it?"

However, Spellman is not about to attack Harris very heavily at this point. When pressed she concedes, "I must admit that I'm a lot more relaxed than I have been in the past."

Harris refuses to throw in the towel. "When I get out and talk to people I'm finding that she isn't all that popular like everyone thinks," he said. "If we can get people to understand that she has voted for higher taxes, voted for a weaker defense (by voting against the B1 bomber) and doesn't have such a good record, we can beat her.

"The problem is getting people to understand her record. All she wants to talk about is the post office in Brentwood or things like that."

Harris' campaign frustration seems to bear out an adage developing among Maryland politicans: "Don't run against Gladys Spellman."

Spellman is well aware of what people say about her, and she is also well aware that her popularity [WORD ILLEGIBLE] her higher on the political ladder

"I love what I'm doing here because I'm still close to the people in district," she said. "I work with tunneral most every day and I really do know almost everyone in the district it seems.

"In the Senate I'd have to cover the whole state and that would mean less personal contact with the people I represent. But I could change my mind later. I won't rule it out."

She does, however, rule out stories that she will retire in two years so state Sen. Steny H. Hoyer, who failed in his bid to win the Democratic nomination for lieutenant governor this year, can take over her seat.

"That's ridiculous," she said. "Steny doesn't even live in my district. Anyway, I'm having too much fun to retire."