(NewsNation) — Vice presidential candidates Ohio Sen. JD Vance and Minnesota Gov. Tim Walz are ramping up their personal and political attacks ahead of what could be the last debate of the 2024 election

Vance, Republican nominee Donald Trump’s running mate, has questioned Walz’s military record, saying he exaggerated aspects of his service. Walz, Democratic nominee Kamala Harris’ running mate, meanwhile, sharply criticized his opponent for his comments after a school shooting in Georgia. Speaking at a rally in Phoenix, Vance said that school shootings are a “fact of life.”

Both candidates have been facing scrutiny for flip-flopping on important issues and catering to their party lines. Politicians on both sides of the aisle say their candidate will be focusing on policy at Tuesday night’s debate hosted by CBS News.

Connecticut Gov. Ned Lamont, a Democrat, said on NewsNation’s “The Hill Sunday” that Walz has to put a “human face” on his and Harris’ emphasis on small businesses, startups and innovation, “as opposed to the big business orientation on the other side.”

Rep. Tom Emmer, R-Minn., on the other hand, said Vance has the issues, such as the economy and border, on his side during an interview on ABC News.

Vice presidential debate rules

CBS anchor Norah O’Donnell and “Face the Nation” host Margaret Brennan will moderate the debate, which begins at 9 p.m. ET.

The debate will last 90 minutes, with candidates having two minutes to answer questions. Microphones will not be muted, and moderators will not be fact-checking either side’s statements, so it’ll be up to the candidates to do that to each other.

After winning a coin toss Thursday, Vance chose to give the second closing statement, giving him the final word, CBS said.

NewsNation The Hill contributed to this report.