LAMONI, IOWA – Ted Cruz escalated tensions with Marco Rubio over the weekend as both presidential candidates continue to rise in recent polls, suggesting his Republican rival “is attempting to mislead voters” with “false” attacks.

“I think Senator Rubio’s campaign is very, very dismayed at conservatives coming together behind our campaign and is attempting to mislead voters in an effort to slow that down,” the Texas senator said before a campaign town hall in Lamoni, Iowa, on Saturday.

Cruz’s response came after a pro-Rubio super PAC released an ad last week attacking Cruz for voting to weaken national security and limit the government’s ability to fight terrorists. The vote referenced is Cruz’s support of the USA Freedom Act, which ended the U.S. government’s bulk collection of phone metadata on Sunday.

PHOTOS - On the Stump: Ted Cruz's Presidential Campaign

The sparring between the freshman senators heightened on Saturday morning when Cruz’s campaign released an advertisement that featured U.S. Rep. Jim Bridenstine (R-OK) calling the ad “despicable” for its depiction of Cruz as voting to weaken national security.

“That’s about as ridiculous a proposition as anyone can imagine,” Cruz said on Saturday, arguing his vote defended the privacy of Americans.

Cruz pushed back and said Rubio is trying to divert the campaign conversation away from immigration.

“Senator Rubio’s campaign has been desperate to change the topic from his longtime partnership and collaboration with President Obama and Chuck Schumer in pushing a massive amnesty plan,” Cruz added.

Cruz began highlighting Rubio’s backing of a Senate-backed comprehensive immigration bill that would have opened up an eventual path to citizenship for undocumented immigrants in the country — what Cruz has called a “massive amnesty plan."

PHOTOS - On the Stump: Marco Rubio's Presidential Campaign

The personal, back-and-forth attacks between Cruz and Rubio increased two weeks ago when Rubio’s campaign fired back, saying Ted Cruz supported an amendment in 2013 that would have opened up a path to legal status for undocumented immigrants.

Last week in Harlan, Iowa, when asked about the proposition of a path to legal status, Cruz said it could eventually be on the table. He told reporters, “We can have that conversation with the American people once we’ve secured the border.”

Cruz and Rubio are both polling in the top four nationally, and as the campaigns anticipate the waffling of Ben Carson and Donald Trump’s supporters, both candidates see an opportunity to garner their former backers.

On Saturday, Cruz also refused to “throw rocks” at Donald Trump over any of his recent controversial comments.

“I’m not going to play the role of theater critic, giving a running commentary on anything and everything Donald Trumps says or any other candidate,” Cruz said.

“I’m not interested in throwing rocks at the other candidates,” he added. “I like Donald Trump – I’m glad he’s running. I think he has energized and excited a lot of people.”

Cruz continues his three-day, 14-stop trip through Iowa on Sunday and Monday.