DES MOINES, Iowa (AP) — Republican David Young has canceled some television airtime reserved for advertisements in his bid for Iowa’s 3rd congressional district, according to documents filed with the Federal Communications Commission this week.

Young, a former chief of staff for Republican Sen. Chuck Grassley, is running against Democrat Staci Appel in one of the nation’s closest congressional races. The seat is open because Republican U.S. Rep. Tom Latham is retiring in the district, which stretches from Des Moines to Council Bluffs.

Young’s campaign cancelled airtime scheduled from Sept. 16 through Sept. 22 on WHO-TV and KCCI-TV, according to contracts the stations provided to the FCC. Young spokesman Tim Albrecht declined comment.

The National Republican Congressional Committee is spending heavily on advertising in the race. Spokesman Tyler Houlton said he didn’t know why the ads were cancelled but expressed confidence about the race. “It definitely does not raise any questions about his abilities,” Houlton said. Isaac Baker, with the Democratic firm AKPD Message and Media, called the move a “very troubling sign for a candidate locked in a tight race this close to the election.”

Young had nearly $90,000 in his campaign account at the end of June. Appel, who didn’t face a competitive primary, had more than $725,000. Young finished fifth in a six-person primary, but won the nomination at a June 21 convention after five rounds of voting.