The chairman of the Prince William Board of County Supervisors said Monday that he plans to officially announce this week that he’s running for lieutenant governor

Corey A. Stewart’s expected announcement Wednesday will not surprise Republicans and conservatives who’ve been following the 2013 races. Stewart has been in campaign mode since December, traveling around Virginia as many as five days a week to line up support.

Stewart is the first candidate to officially jump into the race to replace Lt. Gov. Bill Bolling (R). The campaign for the part-time post will probably get more attention and scrutiny because of the 20-20 split among Democrats and Republicans in the state Senate. That split gives the lieutenant governor a tie-breaking vote on non-budget matters and determines which party controls the Senate.

Stewart (R-At-Large) said he has good reason to begin his campaign early. “I’m fairly well known in Northern Virginia, but I’ve got a lot of parts of the state to visit,” he said.

The board chairman is known for championing the county’s anti-illegal immigration policies. But he said this campaign will focus on economic development as he makes the case that what has worked for Prince William will work statewide.

The county is often ranked in the top five in the country for job growth, but some detractors have noted that many new jobs are low-wage, retail ones.

“I’m going to be focused almost exclusively on doing those things that will create jobs and more economic growth in the state,” Stewart said.

Pete Snyder, chairman of the state GOP’s VA Victory 2012, and former White House technology chief Aneesh Chopra, a Democrat, are widely expected to run for the post. Other possible Democrats being mentioned are state Sen. Ralph S. Northam (D-Norfolk) and Del. Kenneth Alexander (D-Norfolk).

Oakton businessman Keith Fimian (R), a two-time congressional candidate, had also been considering a bid for lieutenant governor, but he said in an interview Monday that he had decided against it.

GOP activists say that because Bolling and Attorney General Ken Cuccinelli II (R) have already announced their 2013 campaigns for governor, other candidates for party slots in the lieutenant governor and attorney general races are looking to solidify plans earlier.

Stewart said he is also announcing early to line up financial donors. Although he has not yet collected any checks for the coming campaign, he said he has lined up support from prominent Republicans and conservatives.

He declined to name the supporters but said he is doing well in the development and construction industries, as well as auto and defense industries around the state.

To run a competitive race, Stewart said he would probably need $1.5 million to $2  million for a primary, if there is one, and perhaps close to $7 million for a general election.

“It will be a very expensive general [election] . . . because of the importance of the lieutenant governor’s race this time around,” Stewart said.

Staff writer Anita Kumar contributed to this report from Richmond.