Related: Campaign flubs: problematic presidential ads on both sides of the aisle  Ted Cruz dared Donald Trump to sue him over a negative campaign ad on Wednesday.  In a press conference before a campaign stop in Seneca, South Carolina, Cruz said he would welcome a lawsuit from his fellow Republican presidential candidate over a campaign ad that the Texas senator recently started airing in the state. The ad features footage from a 1999 interview of Trump with Tim Russert in which the New York real estate mogul said: “I am very pro-choice.”  Cruz, holding a cease and desist letter from Trump’s lawyers, said: “Mr Trump you have been threatening frivolous lawsuits for your entire adult life. Even in the annals of frivolous lawsuits this takes the cake. And so, Donald, I would encourage you, if you want to file a lawsuit challenging this ad, claiming it is defamation, file a lawsuit.”  The Texas senator, a constitutional lawyer who has argued before the supreme court, said that the end result of a lawsuit from Trump over the ad would be “Donald Trump and any lawyer that signs his names to the pleadings being sanctioned for frivolous litigation”.  The ardent conservative expressed his befuddlement that “an ad that plays video of Donald Trump speaking on national television is somehow defamation”. Trump’s “own words said on national television are public record and repeating someone’s own words cannot be defamation,” he added.  In a statement, the Cruz campaign insisted that it would now air the ad with greater frequency.  In a statement after Cruz’s presser conference, Trump upped the stakes. The frontrunner said of his rival: “He is a liar and these ads and statements made by Cruz are clearly desperate moves by a guy who is tanking in the polls - watching his campaign go up in flames finally explains Cruz’s logo.  “I am pro-life and I do not support taxpayer funding for Planned Parenthood as long as they are performing abortions.”  Trump added: “If I want to bring a lawsuit it would be legitimate. Likewise, if I want to bring the lawsuit regarding Senator Cruz being a natural born Canadian I will do so. Time will tell, Teddy.”  The Trump statements from the Cruz ad came in 1999 when he was flirting with a presidential campaign as the candidate of the Reform party. Since then, the real estate mogul has changed his position. Trump said in the August presidential debate said that his shift occurred because “friends of mine years ago were going to have a child, and it was going to be aborted. And it wasn’t aborted. And that child today is a total superstar, a great, great child. And I saw that”.  In a statement on Tuesday, Trump said: “I am a conservative person and I believe in conservative values. Like Ronald Reagan, on many issues, I have evolved. I am pro-life and have been for a long time.”  Related: Ted Cruz v Marco Rubio: campaign fight is getting ugly in South Carolina  The legal battle marked the latest escalation in the ongoing feud between Trump and Cruz. Trump has repeatedly questioned Cruz’s eligibility to run for the presidency and has repeatedly accused the Texas senator’s campaign of engaging in dirty politics.  On Monday, Trump issued a statement calling his rival “a totally unstable individual”.  The real estate mogul said of Cruz: “He is the single biggest liar I’ve ever come across, in politics or otherwise, and I have seen some of the best of them. His statements are totally untrue and completely outrageous. It is hard to believe a person who proclaims to be a Christian could be so dishonest and lie so much.”
Ted Cruz has said he would ‘encourage’ Donald Trump to file a defamation lawsuit over a campaign ad in which Trump (in 1999) says he is ‘very pro-choice’