Suburban Maryland officials, whose communities are home to thousands of federal employees, are pleading for an agreement to avoid what they say are potentially devastating effects of the deep, automatic federal spending cuts that could occur beginning March 1.

Three county executives plan on Tuesday to outline in detail the potential harm they see coming to Howard, Montgomery and Prince George’s counties if the automatic spending cuts, or sequester, take effect. Each jurisdiction has thousands of federal workers who live or work within their borders at dozens of major federal installations.

In a press conference scheduled for 9:30 a.m. Tuesday in Rockville, Democrats Ken Ulman of Howard, Isiah Leggett of Montgomery, and Rushern L. Baker III of Prince George’s will discuss what they say would be devastation close to home.

In Howard County, there are about 50,000 people who either work for the federal government or for related industries, said spokesman Mark S. Miller. Within Montgomery’s borders, there are about 47,000 workers with federal jobs, said Melanie Wenger, the county’s chief lobbyist. And in Prince George’s, where officials often point out that the county supplies 25 percent of the federal workforce in the metropolitan area, at least 71,000 county residents could be affected, said spokesman Scott L. Peterson.