Republican businessman John Brunner's announcement that he will run for the Senate in Missouri is "imminent," according to sources close to him.

Brunner's campaign will immediately shake up what had been a head-to-head campaign between Rep. Todd Akin (R-Mo.) and former Missouri Treasurer Sarah Steelman in their quest for Sen. Claire McCaskillClaire Conner McCaskillOn Capitol Hill, few name names on sexual harassment Democrats scramble to contain Franken fallout  Gillibrand to donate money from Franken's PAC MORE's (D-Mo.) seat, a top Republican target this year.

Brunner's announcement is likely to come sometime after this week.

The wealthy owner of Vi-Jon Laboratories, best known for producing the Germ-X hand sanitizer, Brunner will be able to help fund his campaign.

While he has not previously run for elected office, Brunner has long been involved with Missouri Republican politics. He worked for Pat Buchanan's presidential campaign in 1996 and has donated to many GOP causes over the years.

He and Akin also have a long-standing relationship. Akin spoke at he funeral of Brunner's father in 2006, and Brunner has donated more than $30,000 to Akin's campaigns over the years. As recently as this spring, Brunner described Akin as a "fantastic guy."

A source close to the Akin campaign described the two as "close friends for a long time." He said they have not spoken recently, but that Brunner had long been mulling a run.

"A lot of it has to do with Brunner was expressing interest a long time before Todd was in," said the source. "He surrounded himself with a team of people who said 'you've got to do this, you're the guy to do it,' and once they've got their hooks in you they’re not going to let go."

The source close to Brunner agreed that the two have a good relationship, and said Brunner wants to run because he believes his business experience is needed in the Senate.

"John’s been an Akin supporter for years — Todd’s voting record for the most part is something John appreciates," siad the source. "The question really is, in a time like this is the public looking for and needing someone with a fresh, different perspective altogether, or is it a time for folks who have a whole lot of political and government experience to step forward?"

Democrats have derided Akin as being too conservative for the state and a poor campaigner, and Steelman has come up short in fundraising so far, with less than $200,000 cash on hand for the race.

While Brunner could fizzle on the stump or struggle with handling the spotlight once the campaign gets going, he could be a tougher candidate than the other two, say some Democrats in the state.

"With Brunner, the fact is that he doesn't have a record, he doesn't have the baggage of taking tough votes," said one senior Missouri Democratic official. "In an economy like this having someone walk out and say 'I've created x number of jobs, Claire McCaskill hasn’t created a single one,' that’s pretty good with the economy being the way it is."

But Missouri Democratic Party senior spokeswoman Caitlin Legacki predicted that a tough primary would scuff up Brunner's image.

"The Republican primary is going to be a lengthy and bruising endeavor for anyone who decides to run, but especially for a candidate who would bring his own, unique vulnerabilities to what is expected to be a divisive primary," she said. "Before Brunner can be taken seriously as a candidate, Missouri voters look forward to learning his extremist positions on all the tough issues, as well as taking an in-depth look at his professional background and personal beliefs."

McCaskill won by just a two-point margin in 2006, and Missouri, a swing state, has been trending away from the Democrats — it was one of the only swing states President Obama did not win in 2008, and his approval ratings there are worse than in most traditionally purple states.

The primary will not take place until next August.