HATTIESBURG (AP) — In perhaps his most aggressive comments yet as he fights for a seventh term, U.S. Sen. Thad Cochran declared Tuesday that it would be “dangerous” for Mississippi to elect challenger Chris McDaniel. McDaniel, in turn, accused Cochran of spending “recklessly.”

The back-and-forth underscores the larger battle ahead of the June 24 runoff as Cochran tries to win a seventh-term with the argument that Mississippi can’t afford to lose his seniority and experience, something he said brings federal money back to the state. McDaniel, who is running with national and local tea party backing, says Congress has to spend less, even as he promised this week to “fight for Mississippi.”

Cochran made the remarks at the conclusion of two campaign stops in Hattiesburg, where he visited Forrest General Hospital and the University of Southern Mississippi’s School of Nursing.

McDaniel, a state senator from Ellisville, has built his campaign on making Cochran the face of a free-spending federal government that has amassed more than $17.5 trillion in debt. He directly questioned Cochran’s claim that his seniority benefits Mississippi voters in a campaign stop Tuesday in Meridian.

“Seniority matters, but only if someone is willing to fight,” McDaniel told WTOK-TV. “No one can name a single fight that Senator Cochran has led against Barack Obama. The adults have to enter the room and start making tough decisions. We can’t spend recklessly. Senator Cochran has been spending recklessly for a long time and it has to stop if we’re going to save the country.”

The two men meet in a June 24 runoff after neither got a majority in the June 3 primary. The state Republican Executive Committee will meet Wednesday to certify votes from last week’s primary, officially setting the stage for the runoff.

After a pause, both campaigns released new television advertisements Tuesday. McDaniel appeals to voters to “make history” by backing his platform of repealing President Barack Obama’s health overhaul, as well as cutting debt and taxes. Cochran tells voters he “can do more for Mississippi” if he returns to Washington as part of a Republican majority in the upper chamber.

In Hattiesburg, Cochran returned to questioning McDaniel’s criticism of relief spending after 2005’s Hurricane Katrina.

“He doesn’t want any federal money to be used to help out the people of Mississippi after a hurricane that struck the Gulf Coast,” Cochran said. “So it would be dangerous to elect somebody like that.”

Cochran’s attack is based mostly on an interview earlier this year in which McDaniel said he would “have to review” any hurricane relief bill. “I mean, that’s not an easy vote to cast,” he said. He told the Associated Press this week that he would have supported post-Katrina aid, but pushed for stronger safeguards to prevent “waste, fraud and abuse.”