Maryland Republican gubernatorial hopeful Charles Lollar has chosen Kenneth R. Timmerman, a longtime investigative reporter and conservative political activist, to be his running mate, Lollar said.

The two are scheduled to appear together publicly for the first time Monday during an interview on WBFF-TV, the Fox News affiliate in Baltimore, before traveling to the State Board of Elections in Annapolis to formally file as candidates in the June primary.

Timmerman, a former president of the Maryland Taxpayers Association, unsuccessfully challenged Rep. Chris Van Hollen (D) in the state’s 8th Congressional District in 2012. A former resident of Montgomery County, Timmerman has since moved to Frederick County.

Much of Timmerman’s reporting has focused on the Middle East, and he has lived for stints in Egypt and Lebanon, according to a biography on his Web site. He has written for the conservative monthly magazine American Spectator and for NewsMax Media Inc.

Lollar, a Charles County businessman, said he would incorporate Timmerman’s journalistic skills into his work as lieutenant governor.

“We intend on using Ken as Maryland’s chief investigator to help us uncover all of the excessive spending and misplaced tax dollars,” Lollar said in an interview.

As a candidate, Lollar has proposed eliminating the state’s personal income tax, a move he acknowledges would require major reductions in government spending.

Timmerman said he considers Lollar “the next Ronald Reagan.”

Lollar is part of a crowded Republican primary contest. In a Washington Post poll published last week, nearly six in 10 GOP and GOP-leaning independents said they are undecided.

Larry Hogan, the leader of the watchdog group Change Maryland, had the support of 17 percent of voters, followed by Harford County Executive David R. Craig with 13 percent, Lollar with 10 percent and Del. Ronald A. George of Anne Arundel County with 4 percent.

George plans to announce his running mate on Tuesday, the deadline for candidates to file to run for office. Hogan and Craig have already named running mates and filed to run.