Leading Republican presidential candidates Donald Trump and Ted Cruz traded shots Sunday on the eve of the Iowa Caucus, hoping to persuade the remaining undecided voters in the first-in-the-nation voting.

Both candidates hammered on familiar points, with Trump again questioning Cruz’s citizenship and financial records. Cruz, meanwhile, asked whether Trump is indeed a conservative and suggested that his bluster covers his weakness on issues.

“He’s the height of chutzpah,” Cruz told “Fox News Sunday.” “It’s astonishing. He’s not honest.”

The Texas senator trails the front-running Trump by 5 percentage points, 28-to-23, with the caucus on Monday, according to a Des Moines (Iowa) Register poll released Saturday.

Nine percent of caucus-goers remain undecided or not committed to a candidate. And they are part of a larger group of 30 percent without a first choice or who could be persuaded to pick another candidate, according to the paper.

With Cruz and Trump essentially battling for the social conservative vote to win Iowa, Cruz told Fox News that he’s “thrilled” to be in second place, despite having led Trump in Iowa just a few weeks earlier.

Trump told Fox News about the race: “We had a great week and maybe even a great couple of weeks in Iowa. … There's been some very special things happened over the last two weeks.”

However, both candidates, like essentially all of the Democrats and Republicans in the race, made clear that voter participation is now the deciding factor.

“It’s all about turnout,” Cruz said Sunday.

Trump, a billionaire businessman and first-time candidate, jokingly told Iowans while on the campaign trail this weekend that they should cast a ballot Monday regardless of any unexpected personal crisis, even a spouse leaving.

He also questioned again whether Cruz indeed didn’t know he had a dual U.S.-Canadian citizenship, which Trump has repeatedly argued could, in part, disqualify Cruz from becoming president.

“He didn't even know he was a citizen of Canada until 15 months ago?” Trump said. “Give me a break.”

Trump also said he didn’t like the Supreme Court decision that allows for same-sex marriage because such a decision should be made at a state level so he would “strongly consider" appointing justices to overrule the high court decision.