A source tells the Associated Press that Congressman Tom Cotton will announce next week that he's challenging Democratic U.S. Senator Mark Pryor.
Cotton scheduled an event with supporters next Tuesday in his hometown of Dardanelle.
A person who's spoken with Cotton says the freshman congressman intends to enter the race against Pryor, a two-term incumbent who faces re-election next year.
The person who spoke to The AP was not authorized to speak publicly about the planned announcement and spoke on a condition of anonymity.
Cotton was elected to the U.S. House in 2012, to the open seat formerly held by Democrat Mike Ross. Ross is now running for Arkansas governor.
UPDATE: Senator Pryor's Campaign Manager Jeff Weaver released a statement about Cotton's anticipated run:
"In seven short months, Tom Cotton's reckless and irresponsible voting record has alienated Arkansas farmers, seniors, students, women, parents and the business community by voting against such measures as the Farm Bill, Student loans, the Violence Against Women Act, and trying to cut Social Security and Medicare."
"Instead of putting Arkansas first, he has put his own political career ahead of the people of Arkansas and sided with Washington insiders and special interests. When the people of our state review Tom Cotton's record, they won't like what they see."