The Republican National Committee plans to lay off about 25 percent of its full-time workers this week, party officials said yesterday.

The staff layoffs, which could come as early as today, are termed a "restructuring" by Republican officials. They come barely a week after a midterm election that many politicians regard as a disappointment for President Bush and his party.

Mary Matalin, Republican National Committee chief of staff, said the national headquarters staff of about 300 full-time employees would be reduced by at least one-fourth and an unspecified number of part-time workers would also be let go. Those being dismissed will remain on the payroll until the end of next month.

She denied that the cutbacks were related to the party's performance in this month's election, which may have set back the party's hopes for gains in legislative redistricting in 1991.

"It has to do with the fact that next year is going to be a bad year {financially}," she said. "The year between a midterm and a presidential election is always a rough year."

Another party official, who asked not to be identified, said the consensus at the White House and among top-level party staffers was that the national party has "got to get back down to a Mazda, as opposed to a Cadillac."

Some of the layoffs will hit the committee's legislative strike force, part of the GOP's ambitious "1991 Plan" to reverse the Democratic Party's advantage at the state level, where new district lines will be drawn next year. Instead of strengthening GOP control of state legislatures, last week's election increased the number of chambers held by Democrats.

During the next two years, the committee will concentrate its efforts on research and communications and on adding Republican voters at the state level, Matalin said. "Anything that doesn't fit those objectives" will be deemphasized, she added.