A scene from one of the ads. YouTube/screenshot A super PAC supporting Sen. Ted Cruz (R-Texas) launched a pair of new TV ads on Monday aiming to bolster the senator against real-estate developer Donald Trump.

Both ads feature old footage of Trump, the Republican presidential front-runner.

One of the commercials used 2014 footage of Trump praising Cruz. The other touted a 1999 interview in which Trump described himself as strongly in favor of abortion rights.

"Donald Trump is not a conservative because he's extreme on abortion," the narrator in the latter ad declared.

Trump has since changed his position and notes, when asked about the 1999 interview, that former President Ronald Reagan was also once a Democrat.

But Kellyanne Conway, president of Keep the Promise I, the pro-Cruz super PAC, said in a statement that supporting partial-birth abortion should be disqualifying even if a candidate changes his or her position.

"It doesn't take them 15 years to see it is a barbaric practice that takes the life of a child in the final weeks of pregnancy; they know it right away," Conway said. "The life of a child at eight or nine months gestation is not a political football; it is a matter of principle and conscience."

Trump and Cruz had long refused to criticize one another. But about three weeks ago, their détente melted, and the two candidates have been ripping each other to shreds on the campaign trail. They are both competing to finish first in the February 1 Iowa caucus, just seven days away.

Last Friday, both Cruz and Trump released negative ads against one another.

According to Keep the Promise I, the super PAC's new ads are part of a previously announced $2.5 million ad campaign in Iowa and South Carolina.

View the PAC's ads below: