If your next-door neighbor on the left isn't a government worker, chances are the one on the right is. And chances are that your neighbor is more than a little fed up with being painted as a shiftless so-and-so feeding at the public trough.

Over the last decade in particular it's become fashionable for some politicians, Presidents Carter and Reagan most notably among them, and more taxpayers to attribute government's failings to the people who work for it.

Those criticisms have carried a special sting in the Washington area, where more than one-third of the workers are employed by federal, state or local government. But this week those workers will have someone speaking up for them.

Tomorrow a coalition of public employe organizations will stage a downtown rally to proclaim the contributions of public servants and commemorate the 100th anniversary of the creation of the modern U.S. civil service system.

The rally, set for 12 noon at the D.C. Convention Center, will begin a week-long tribute to the nation's 16 million public service workers, some 620,000 of them in the Washington area, for whom Congress and President Reagan have declared Public Employees Appreciation Day on Jan. 17.

Organizers of the rally had hoped that either Reagan or Vice President Bush would be the featured speaker. But as of yesterday, the White House had yet to indicate who, if anyone, would attend the event. Sen. John Warner (R-Va.), D.C. Mayor Marion Barry, Rep. Patricia Schroeder (D-Colo.), Kenneth Blaylock, president of the American Federation of Government Employees, and National War College Vice President L. Bruce Laingen, a former hostage in Iran, are among the speakers scheduled.

The salute, which coincides with the centennial of the 1883 Pendleton Act establishing the U.S. merit system, couldn't come at a more appropriate time, according to its organizers and supporters.

"It's not the public employes' fault for policy or government failures that have been laid on our backs," says G. Jerry Shaw, who heads the Public Employees Roundtable, the 26-group coalition sponsoring the rally.

Shaw, a former helicopter pilot in Vietnam who is president of the Senior Executives Association, likens the attacks against public employes to those directed against veterans of the war.

"The country is finally understanding that the blame for the Vietnam War, if any blame is to be assessed, is not the blame of those who fought it but of the policy makers," Shaw says. "And the same is true for public employes . . . . We do our jobs, and we deserve to be treated with respect."

Federal workers, in particular, have borne the brunt of a hostile public's antigovernment criticisms and seen their jobs, pay and benefits threatened by various policy shifts and political struggles.

"There's been too much scapegoating," complains John Sturdivant, executive vice president of the American Federation of Government Employees, which represents more than 700,000 workers and is the nation's largest federal employe union. "And once it starts, it's very easy to jump on the band wagon."

Sturdivant defends the image of federal workers, saying they "are America" because they are doing the bidding of Congress.

"Federal workers are not nameless, faceless bureaucrats who impede progress with red tape--they're the people who make sure the meat we eat is healthy, the cars we drive are safe, the country is secure and the Social Security checks are on time," he says.

State, county and municipal workers feel "just as embattled sometimes," according to representatives of those groups. They have a somewhat better image with the public because there is more opportunity for personal contact, especially on the local level. But their ranks, like those of federal workers, have declined in the face of budget cuts, and they are more likely to have to deal with the public when the squeeze is put on services.

"It's a two-way sword," says Philip Sparks, a spokesman for the American Federation of State, County and Municipal Employees, which represents 1 million public employes nationwide. "The public sees them, but it sees them understaffed. Our people patch the pot holes and run the mental health facilities and the school-lunch programs, and sometimes they are seen to have caused problems that can be traced directly to policy makers in Washington."

The Washington area, with a total work force of more than 1.6 million, has 405,000 federal employes, including 60,000 military personnel, according to figures from the U.S. Census Bureau and the Metropolitan Washington Council of Governments. The total work force for local governments is about 150,000, and state employes living in the region number about 65,000.

State and local employes account for about 10 percent of the region's total work force. Despite a loss of 18,300 public sector jobs between January and July last year, the D.C., Maryland and Virginia governments, including county and municipal jurisdictions, are considered the region's second-largest employer, after the federal government.

The average pay for full-time federal employes is about $27,700. For Virginia and Maryland state workers the average pay was about $16,600 and $16,000 respectively in October 1981, the most recent year for which figures are available.

Local government workers in Virginia earned at an average annual rate of $15,400 in 1981, while local workers in Maryland earned an average of $19,600 for the same period. Local workers in the District of Columbia earned about $23,300.

According to 1980 census data, the District of Columbia government employs nearly 52,000 workers. In suburban Maryland, including local government jurisdictions within the counties, Montgomery County employs more than 27,000 people; Prince George's County, about 26,000; and Charles County, nearly 3,200. In Northern Virginia, Fairfax County, including Falls Church and Fairfax City, employs about 24,000; Arlington, more than 5,200; Alexandria, nearly 3,400; Prince William County, including Manassas and Manassas Park, about 6,100, and Loudoun County, about 2,500.