The two candidates in the closely watched Colorado Senate race went on the attack in a second debate Friday, after an uneventful first debate Tuesday.

Sen. Michael Bennet accused Republican opponent Joe O'Dea of being a "liar" after O'Dea sought to portray his record in Washington as ineffective and closely aligned with President Biden and national Democrats.

THE SLEEPER SENATE RACES THAT MAY DETERMINE WHETHER DEMOCRATS OR REPUBLICANS CONTROL THE MAJORITY

"Joe, you know that your assertion that I've only passed one bill in the time I've been in the Senate — you've said it over and over again, it's been fact-checked as false over and over again, you're running a TV ad saying it over and over again," Bennet said, during a part of the debate when the candidates asked each other questions.

Joe O'Dea accepts Senate nomination

Joe O'Dea, a construction company CEO and first-time candidate for office, celebrates the Republican nomination for U.S. Senate. (Hyoung Chang/The Denver Post)

"Tell me what that means to you," Bennet said.

"It just goes to your effectiveness. You're ineffective," O'Dea responded. 

COLORADO SENATE SHAKEUP: JOE O'DEA RESPONDS TO SEN. BENNET'S ABORTION ATTACK AD

As Bennet attempted to get a better answer, O'Dea dismissed the senator, repeating that he found him ineffective. 

"You're a liar, Joe," Bennet repeated over protestations from O'Dea. "You're a liar, Joe."

Sen. Michael Bennet

Sen. Michael Bennet, a Democrat from Colorado, speaks during a news conference at the U.S. Capitol in Washington, D.C., July 15, 2021. (Al Drago/Bloomberg)

O’Dea, a Denver area construction company owner and first-time candidate, is challenging Bennet, a former superintendent of the Denver Public Schools who has held the Senate seat in Colorado since 2009, in a race that could become one of a handful that determines if Republicans win back the chamber's majority in next month’s elections.

In the debate, he stood by his earlier statement that he would oppose former President Donald Trump if he ran for president again in 2024: "I said what I said."

Screenshot from Colorado Senate debate between Michael Bennet and Joe O'Dea is seen

Democratic Sen. Michael Bennet and Republican Joe O'Dea faced off in a Colorado Senate debate Friday.  (Courtesy: KUSA/9NEWS)

Bennet likewise sought to distance himself from those in his own party, saying Biden made a "serious mistake" lifting Title 42, traveling to Saudi Arabia and the student loan handout.

"I don't think he should have done it the way he did it," Bennet said of the student loan handout. "And I said that before, and I said it after. You know, I think that they did make it more targeted than they were originally, but it wasn't nearly what I thought they should do, which was do it for the people that need it the most, the poorest people in our country that have that debt and not go above median family income."

O'Dea asked Bennet directly if he regretted voting for big-spending bills. Bennet replied,"I regret the inflation that people are facing."

COLORADO GOP SENATE CANDIDATE TORCHES DEMOCRAT OPPONENT FOR BEING ‘RUBBER STAMP’ FOR BIDEN'S POLICY FAILURES

An average of all the latest public opinion surveys in the race compiled by Real Clear Politics puts Bennet up 7.7 points over O’Dea.

O'Dea has made an effort to paint himself as a working man of the people with a strong connection to Colorado.

Watch more Colorado Senate debate highlights:

Bennet has fought to push back against this characterization — in August, Bennet questioned whether O’Dea was as in touch with working class Coloradans as he claimed.

CLICK HERE FOR THE FOX NEWS APP

"This is a guy who literally posted on Facebook a picture of him and his wife riding their horses to buy sushi in his fancy neighborhood," Bennet said on MSNBC.

Fox News' Houston Keene contributed to this report.