Washington(CNN) Marco Rubio says Ted Cruz is a liar -- accusing the Texas senator of false attacks over same-sex marriage, Planned Parenthood, immigration, campaign tactics and more.
"There's no other way to describe that -- it's a lie. When you say something that's not true, it's called a lie. That's the definition of it," Rubio said Sunday in an interview with CNN's Dana Bash on "State of the Union."
"On this campaign, he is saying things that are not true, and he's saying it repeatedly, and he knows they're not true," Rubio said.
Rubio unloaded on Cruz just days ahead of South Carolina's Republican primary, a key battle that could winnow the field of six GOP presidential contenders.
Moments from Marco Rubio's career
Florida Sen. Marco Rubio speaks in October 2013 at the Values Voter Summit, held by the Family Research Council in Washington.
Sen. Mike Lee, left, and Rubio talk before a news conference to introduce their proposal for an overhaul of the tax code in March.
Rubio, center, arrives in the House chamber ahead of Israeli Prime Minister Benjamin Netanyahu's address to a joint meeting of the U.S. Congress in March.
Rubio speaks with the media after delivering remarks during the graduation of small business owners from the Goldman Sachs 10,000 Small Businesses program held in Miami in February.
Rubio talks to aides in December before speaking on President Barack Obama's announcement about revising policies on U.S.-Cuba relations.
Rubio, left, talks to Sen. Lindsey Graham prior to a news conference on Capitol Hill in July.
Rubio talks to reporters in June after a closed door briefing on Capitol Hill.
Rubio speaks to the media in front of a wall dedicated to the victims of the violence in Venezuela as he shows support for the Venezuelan community at a restaurant in Doral, Florida, in April 2014.
Rubio speaks to the media at the Doral restaurant in April 2014.
Rubio checks his phone in March as he arrives for a Capitol Hill news conference to introduce a proposal for an overhaul of the tax code.
Rubio, left, is greeted as he arrives at a restaurant in Doral in February 2014.
Rubio, left, and Florida Gov. Rick Scott speak to the media in Doral in February 2014.
From left, Sens. Cory Booker, Rubio, Kristen Gillibrand and John McCain wait for Obama to deliver the State of the Union address in January 2014.
Rubio addresses an event held by the American Enterprise Institute for Public Policy Research in January 2014.
Paralympian Brad Snyder poses with Rubio during a Team USA Congressional visit in November 2013.
Rubio speaks in November 2013 during a campaign stop for Virginia Attorney General Ken Cuccinelli, the Republican candidate for governor of Virginia.
Rubio confers with McCain as U.S. Ambassador to Syria Robert Ford testifies before the Senate Foreign Relations Committee in October 2013.
Rubio, center, speaks to members of the media as Sen. Ron Johnson, left, and Rep. Ron DeSantis listen during a news conference on Capitol Hill in October 2013.
Rubio returns to the Capitol after meeting with Obama and other Republican leaders about the government shutdown in October 2013.
Rubio speaks to an aide on Capitol Hill as he arrives for the weekly Senate Republican Policy Committee luncheon in September 2013.
His verbal assault came the morning after the two had one of the most memorable exchanges of Saturday night's debate hosted by CBS, when Cruz attacked comments Rubio had made on Univision in Spanish about immigration.
Rubio shot back that Cruz doesn't even speak Spanish -- and Cruz responded in Spanish, challenging Rubio to continue their exchange in the language.
Asked if Rubio was calling Cruz's Latino status into question, Rubio responded: "No, I was calling into question whether he even knows what I'm saying ... He has no idea. He's just going off what other people are telling him, and it's false. It's just not true."
He invoked a long list of what he called Cruz's false characterizations of his record -- as well as Cruz's campaign's tactics portraying rival Ben Carson as dropping out of the race as Iowa's caucus-goers were still voting.
"The bottom line is, there's been this disturbing pattern the last couple of weeks of Ted Cruz saying things that are not true. Just in the last week, he's lied about my record on marriage. He's lied about my record on Planned Parenthood. Of course he lied about Ben Carson in Iowa. Last night Donald Trump says he's issuing robocalls, doing the same thing to him. And then he also isn't telling the truth about immigration," Rubio said.
The Florida senator also accused Cruz of misrepresenting himself on immigration.
Texas Sen. Ted Cruz
U.S. Sen. Ted Cruz has quickly made a name for himself. Since taking office in 2012, the Texas Republican has solidified his brand as a conservative firebrand willing to take on establishment members of the GOP.
Cruz speaks during the Republican National Convention in Tampa, Florida, in August 2012.
Vice President Joe Biden administers the Senate oath to Cruz during a mock swearing-in ceremony in January 2013. Cruz was accompanied by his wife, Heidi Nelson, and his two daughters, Caroline and Catherine.
During a news conference in March 2013, Cruz announces a plan to defund the Affordable Care Act, also known as Obamacare.
Cruz heads to the weekly Senate Republicans policy luncheon in Washington in March 2013.
Cruz speaks during the National Rifle Association's Annual Meeting and Exhibits in May 2013.
Cruz speaks during the "Exempt America from Obamacare" rally in Washington in September 2013.
Cruz emerges from the Senate chamber after spending more than 21 hours railing against Obamacare in September 2013.
Cruz speaks to reporters on Capitol Hill in October 2013.
From left, U.S. Sens. Lindsey Graham, John McCain and Cruz listen as President Barack Obama delivers his State of the Union address in January 2014.
Cruz leaves a briefing at the U.S. Capitol in June. The briefing was about the prisoner exchange that freed Army Sgt. Bowe Bergdahl from the Taliban.
From left, Cruz attends a Capitol Hill news conference with U.S. Reps. Marsha Blackburn, John Carter and Lamar Smith in September. Cruz discussed immigration reform at the news conference.
U.S. Sen. Pat Roberts, center, is joined by Cruz and former Sen. Tom Coburn at a rally in WIchita, Kansas, in October.
Cruz poses for a selfie following his February speech at the Conservative Political Action Conference in National Harbor, Maryland.
A woman piles up Cruz stickers during the Conservative Political Action Conference.
Cruz speaks Tuesday, March 10, during the Alfred K. Whitehead Legislative Conference and Presidential Forum in Washington. Prospective presidential candidates from both political parties participated in the forum.
"Late Night" host Seth Meyers interviews Cruz on Monday, March 16.
Cruz brings his daughters Caroline, left, and Catherine on stage during a walk-through Sunday, March 22, at Liberty University in Lynchburg, Virginia.
On that same stage, Cruz officially announces his campaign for the presidency on Monday, March 23.
"I mean, he goes around portraying himself as this purist -- you know, Ted Cruz, the purist on immigration. But I was there two, three years ago, when he was passionately arguing at the committee that we needed to pass immigration reform and needed to bring people out of the shadows," Rubio said.
He added: "I think this pattern of saying things that aren't true has become very disturbing when it comes to Ted Cruz's campaign."
During the interview, Rubio also said he supports Senate Majority Leader Mitch McConnell's position that the chamber won't consider a nomination President Barack Obama submits to replace Supreme Court Justice Antonin Scalia, who was died Saturday.
"I don't think the Senate's going to move on it, and I agree with that decision," Rubio said.
He said it's been 80 years since a Supreme Court choice was nominated and confirmed in the year of a presidential election. Justice Anthony Kennedy was confirmed on February 3, 1988, but that was after the nomination of Robert Bork was rejected.
"There's a reason for that, and the reason is that the next president should have a chance to fill that void, and not someone who's never going to answer to the electorate again," Rubio said.
He added: "Let's let the voters weigh in in November, and then we'll have an appointment."