Prince George's County Republicans, convinced they can regain the congressional seat lost seven years ago to Gladys Spellman, are maneuvering to find a consensus candidate and avoid a bitter primary battle in the special election this April. But the unity effort apparently is threatened by charges that County Executive Lawrence Hogan has been resorting to pressure tactics to clear the field for his 24-year-old son Lawrence Hogan Jr.

According to one of the potential GOP candidates, John Burcham, close associates of Hogan and other Republicans told him that he would have difficulty raising money, remaining in the good graces of the county Republican party, and possibly retaining his part-time $20,000 job as head of the Park and Planning Commission if he decided to run in the 5th District primary against the junior Hogan.

At the same time, Audrey Scott, who already has declared for the seat, said she was told by a top Hogan aide that a three-month county job she has at Prince George's General Hospital and Medical Center would not be extended, despite earlier assurances that it would. Scott also said that Hogan told her that if she decided not to run there was the possibility that an attractive job could be found for her somewhere else in the county government.

Scott said yesterday a Hogan aide had called her this week after it became clear she intended to run in the Republican primary, to say that her 700-hour job as a volunteer organizer at the hospital was not being extended and that she should talk to the conty executive if she had any problems with the termination. Scott said she then met Friday with Hogan, who told her that "since the job was being terminated there was a possibility of other jobs in the county govermnent much more to my liking."

According to friends of Scott, Hogan offered during the meeting to make her a department head. Scott said that Hogan also told her during their private meeting in his office that "an uncontested primary is the only way to go because he got burned in a contested one [when he lost the 1974 Republican gubernatorial primary to Louise Gore] and he didn't want his son burned in one."

On Friday, Burcham said that long-time supporters of the Hogan family had approached him on behalf of Hogan Jr. and asked that he back off because it would cause problems for the part, and possibly for Burcham's future political plans. He said he had heard rumors from Republican friends that Hogan would attempt to force him to resign his planning board job if he ran against Hogan Jr. in the April 7 primary. Burcham noted, however, that the county executive never personally spoke to him about that race or his job.

The junior Hogan said of the alleged pressure tactics: "I can't believe that's true. If it were true, it was a stupid thing to do." Young Hogan has not officially declared for the seat his father held from 1968 to 1974 but is considered to be the strongest Republican candidate because of his name. He has already hired a national consultant -- the Virginia-based firm of Black, Manaford and Stone -- and his father's long-time fund-raisers have been collecting checks for the expected race.

Hogan Sr., a Republican national committeeman who is gearing up for his own race for the U.S. Senate in 1982, yesterday denied that he had tried to pressure any of the other candidates to get out of the race or had made any job offers.

"That's the dumbest thing I've ever heard," said Hogan. "Audrey [Scott] asked to see me after her job ran out and she came in talking about the race and talking about jobs. I don't think Audrey is any threat and Larry's campaign manager thinks it would be better to have her in the race because then you would get coverage." Hogan also said he had not talked to Burcham but considers him the only potential threat to his son in a primary.

The charges and counter-charges that surfaced this week have jeopardized the Republican strategy of finding a consensus candidate and avoiding a bitter primary. Such a strategy, Republican leaders say, would allow the party to take advantage of a division among the Democrats that an expected crowded primary race could cause. Already, a dozen or so Democrats have declared or expressed an interest in filling Spellman's seat.

In an effort to unite behind one Republican, state Republican leaders, who see the race as a test of President Reagan's initial days in office, have spoken this week of trying to bring together the four prospective Republican candidates -- Hogan Jr., Scott, Burcham and Kevin Igoe, who unsuccessfully challenged Spellman last November -- and have three of them withdraw.

Such a scenario seems unlikely, however, since all four met this week with officials at the Republican National Committee and the Republican Congressional Campaign Committee to discuss their individual races and receive advice about how to run a campaign.

Like the state Republican leaders, the national officials believe there is a possibility that the Spellman seat can be won by a Republican if the race is well funded and managed. The national officials are waiting for the results of a poll being done by Hogan Jr. to decide what sort of shot the Republicans have at the seat and how intensely to pursue it.