Marco Rubio said on Tuesday that the millions of dollars being spent on negative advertising against him, specifically by Jeb Bush backers, amounts to "almost free advertising for Hillary Clinton."

"If you add up all the money that's been spent against every other candidate, it does not equal to what's been spent against me: over, close to 30 million dollars now of attack ads, mostly from Jeb Bush," Rubio told Iowa radio host Simon Conway. "No one else has faced anything close to that, not Donald Trump or Ted Cruz or anyone else."

Rubio was referring to money being spent by Right to Rise, the super PAC supporting Bush. The Rubio campaign said last week that $20 million of the $22 million spent against it had come from Right to Rise.

In the interview, Rubio said that personal attacks against him would ultimately help Clinton as the Democratic nominee.

"Look, if there are policy differences, that should be debated and discussed," the Florida senator said. "But when it gets to the personal stuff, which is what we're starting to see now, that's not good for the Republican party and it's almost free advertising for Hillary Clinton."

Rubio initially raised the attack ads in response to a question about whether he was "the establishment candidate," a label he has sought to distance himself from.

"If you look at it, Jeb Bush, for example, is spending one million dollars a day attacking me, a million dollars a day attacking me," Rubio said. "Every penny of that came from establishment donors. He's raised over a hundred million dollars for a super PAC."

Rubio compared the attacks to those he faced when running against Florida Gov. Charlie Crist for Senate in 2010, a race in which Rubio received Jeb Bush's endorsement.

"Look, $22 million spent attacking me is $22 million Hillary Clinton isn't gonna have to spend," Rubio said. "In the end, the attacks often are maybe not effective, but that's not the point — the point is, I'm not complaining, this is part of the process. I'm more than happy to take this on. I knew I would. It's not dissimilar from what I faced when I ran against Charlie Crist in Florida. They spent a lot of money there as well."