With less than three weeks left until the Aug. 24 primary, at least two of the three major GOP gubernatorial candidates are flooding the TV airwaves in an eleventh-hour battle for votes.

Gov. Sean Parnell, who had secured no TV spots until recently, has now ordered hundreds of spots on Anchorage, Juneau and Fairbanks area channels, according to public files kept by network and cable stations. Parnell's air time adds up to more than $46,000, the records show.

Political strategists say he's waited a little long to get into the TV game; most of the cost-effective spots have already been snapped up by other campaigns. Consultants say in Alaska in the summer, the best times to air ads are in the morning or later at night because people generally take advantage of the long hours of daylight and don't settle in to watch TV until later. More expensive prime time spots -- one ballot measure campaign is paying $1,500 for 30 seconds on "America's Got Talent," compared to $30 on the daytime Ellen DeGeneres show -- are not considered the best use of the campaign's money.

Parnell's initial TV spot, which has been airing for a few days now, touts his record of accomplishment in the year since he took over the governor's post from Sarah Palin, who abruptly resigned.

Anchorage attorney Bill Walker also is beefing up his media, according to his campaign, airing a new spot that reiterates Walker's primary campaign theme to "stop studying and start building" a gas line from the North Slope to Valdez.

Walker has already spent more than $87,000 on media buys since February, campaign finance disclosure records show.

Campaign spokesman Taylor Bickford said the campaign is "significantly beefing up" the TV advertising in the last couple weeks of the race. Although the most recent publicly released poll showed Parnell with a significant lead over Walker and former legislator Ralph Samuels, Bickford said Walker believes the political tide is turning headed into the home stretch.

"We feel like our momentum is peaking right now and our hard work over the last few months is paying off," Bickford said.

He noted that in recent weeks Parnell has started targeting Walker -- not Samuels -- in his campaign speeches and press releases, suggesting that even Parnell sees Walker as the bigger threat at this point.

"This is crunch time," Bickford said. "We're happy with our strategy."

Samuels' campaign didn't immediately return a call for comment for this story.

Contact Patti Epler at patti(at)alaskadispatch.com.