Fairfax County Supervisor John W. Foust will launch a campaign this week to unseat Rep. Frank R. Wolf, becoming the best-known Northern Virginia Democrat to challenge the veteran Republican lawmaker in many years.

Foust said he will file paperwork Tuesday. He has represented the Dranesville district, encompassing McLean, Great Falls, Herndon and parts of Vienna, on the Fairfax board since 2007. He is gambling that the memory of October’s 16-day federal government shutdown will prompt voters to toss out a congressman who has won reelection with relative ease for three decades.

“I’ve been thinking about it for awhile, and I think the thing that caused me to actually do it was the government shutdown,” Foust said in an interview Monday. “I find it totally unacceptable the way they’re operating in Washington.”

Foust plans to contrast the work he has done with Republicans on the board with the hyper- partisanship and “dysfunction” of Capitol Hill, he said. The question is whether he can tie those traits to Wolf, who has maintained a reputation as a relative moderate and has reached out to federal workers and made federal transportation funding for the region a priority despite Democrats’ efforts to highlight his more conservative stances.

Foust will be the third Democratic candidate in the race for the 10th Congressional District, which stretches from McLean to the West Virginia border and includes all of Loudoun County, portions of Fairfax and Prince William counties and the westerly outpost of Winchester. The district is more Republican overall than the portion of it that overlaps with Foust’s supervisor district.

Fairfax lawyer Richard Bolger and Leesburg architect Sam Kubba are also running, though national Democrats are privately hopeful that Foust will win the nomination.

Wolf, who declined to comment for this story, has long been an elusive target for Democrats — although his district remains competitive in presidential and gubernatorial races despite being redrawn after the latest census to be a bit safer for the GOP.

In last month’s race for governor, Attorney General Ken Cuccinelli II (R) bested Terry McAuliffe (D) by less than 1 percent in the 10th Congressional District. In 2012, Mitt Romney (R) narrowly edged out President Obama in the district.

Nonetheless, Wolf has won decisive victories against a succession of inexperienced or underfunded Democratic challengers.

He beat lawyer Kristin Cabral (D) with 58 percent of the vote in 2012 and retired Air Force Col. Jeff Barnett (D) with 63 percent in 2010. National Democrats mobilized behind a well-funded challenger, Georgetown University professor Judith Feder, in 2006 and 2008, but she lost by double-digit margins both times.

Foust, 62, will be the first sitting elected official to challenge Wolf since 1986, when the Republican beat then-Arlington County Board Chairman John G. Milliken. Originally from Johnstown, Pa., Foust has lived in Northern Virginia since 1981 and resides in McLean. He practiced construction law until winning his seat on the Fairfax board.

Wolf is the perennial subject of retirement rumors, both because he is 74 and because he tends to raise little campaign cash in non-election years. Through Sept. 30, Wolf had taken in $212,000 and had $284,000 in the bank — relatively small numbers for a lawmaker from an affluent district who sits on the powerful House Appropriations Committee.

Wolf says he is running for an 18th term and has given little hint about his retirement plans. When he does leave office, a host of high-profile Republicans and Democrats are likely to try for his seat — so Foust could help himself for a future race by putting up a good fight this cycle even if he loses.

Foust spent $325,000 on his 2011 supervisor campaign, far less than a competitive congressional bid will likely cost, although he said he thinks he can raise the necessary cash because “there’s going to be a lot of excitement” for his campaign.

Foust thinks the shutdown, which affected thousands of federal workers and scores of contractors in the district, has eroded Wolf’s standing in Northern Virginia. Yet Wolf spoke out against the shutdown early on, making clear the day it began that he wanted Congress to pass a “clean” bill to reopen the government without cutting funds for the new health-care law.

To Foust, that wasn’t enough.

“He did nothing to stop it from happening,” Foust said. “It’s a typical Frank Wolf move — you get what you want and then cover your bases by coming down on the other side of he issue as well.”