Republican Rep. Frank R. Wolf of Northern Virginia has an 11-point lead over his Democratic rival Ira M. Lechner, and is more popular with independent voters and federal workers than Lechner, according to a poll released yesterday.

The Associated Press/WRC-TV poll shows that Wolf, who swept into office two years ago with the Reagan landslide, has a 48-to-37 percent lead over Lechner, a former state legislator from Arlington, with 12 percent undecided.

Only 1 percent of the 270 likely voters polled last week said they would support someone else, indicating that the third candidate in the race, Libertarian Scott R. Bowden, has virtually no support.

The poll, the first released on the 10th District race, has a 7 percent margin of error. It shows Wolf with a narrow 42-to-39 percent margin among federal employe households, a major voting bloc in the affluent district that has the nation's largest number of active and retired government workers. Thirteen percent of those polled said they were undecided and 6 percent said they did not plan to vote.

Those results differ markedly from a poll in the neighboring 8th District, which shows former Democratic congressman Herbert E. Harris II with an 8-point lead over incumbent Rep. Stanford E. Parris. That poll showed Harris was far more popular with households containing federal workers than Parris.

Lechner said yesterday he was "very encouraged by the fluid aspect of the race." Bob Chase, a Wolf strategist, said the survey generally confirms the candidate's own polls showing Wolf is more popular with independent voters.

The AP poll shows voters sharply divided along party lines: 76 percent of Republicans and 73 pecent of Democrats are supporting their party's candidates, but Wolf holds a 2-to-1 lead among independents. Of the independents surveyed, 51 percent favor Wolf, 26 percent support Lechner and 21 percent are undecided.

"The fact is we have not delivered our message because I am a believer in late delivery," said Lechner. He said he plans to spend the final 19 days of the race doing that through direct mail appeals. "This poll shows how much more we can accomplish and how volatile this election is."

Wolf's campaign manager, Tom Moor, agreed. "We've been saying all along this is a close race, it's always a close race in this district. Frank is going to be talking about his record and working very hard. We're not going to be complacent or take anything for granted," he said.

Recently Wolf's campaign, fearing that overconfidence might doom his chances, sent a letter signed by Wyatt B. Durrette Jr., a Fairfax lawyer who was defeated in last year's race for state attorney general. Durrette, who is regarded as very popular in Northern Virginia, wrote: "I'm deeply concerned that too many people are telling Frank Wolf that he's also a sure winner." Durrette warned that "Ira Lechner is working around the clock and has a cadre of union and liberal activists" working against Wolf.

"To call Wolf's a comfortable lead would be stretching it," said a spokesman for NBC News in New York, which conducted the poll for the AP and WRC-TV. "But these results are more typical than the Harris-Parris race: the incumbent is leading and Lechner probably doesn't have the same name identification Harris does."

The new polls indicate that Wolf may be more popular among members of his own party than Parris, although both are Reagan supporters with similar voting records. Among Republicans, 76 percent are supporting Wolf but only 65 percent are backing Parris.

The poll also suggests Lechner, a Washington labor lawyer with a liberal reputation, has not made the inroads among conservatives that Harris has. Among conservatives, who comprise about one-third of the sample, 31 percent say they are supporting Harris but only 12 percent favor Lechner.