Donald Trump. Alex Wong/Getty Images Real-estate magnate Donald Trump on Friday morning found a new way to take a jab at the faith of Sen. Ted Cruz (R-Texas).

"How can Ted Cruz be an evangelical Christian when he lies so much and is so dishonest?" the Republican presidential front-runner wrote on Twitter.

Trump and Cruz have taken numerous shots at each other this week as they compete for conservative votes in South Carolina, the next GOP primary state.

Cruz launched an attack ad accusing Trump of having "a pattern of sleaze stretching back decades." The commercial focused on Trump's support for eminent domain, or the government's power to seize private property.

Among other things, Trump accused Cruz of lying when the senator denied being behind "push polls" apparently conducted on his behalf. According to The Washington Post, a robocall in South Carolina criticized the non-Cruz candidates in the race.

"Cruz caught cold in lie after denial of push polls ... How can he preach Christian values?" Trump tweeted Thursday.

After a long détente, the two candidates have repeatedly attacked each other since December. At two points that month, Trump brought up Cruz's Cuban ancestry to also take a roundabout jab at his faith.

"To the best of my knowledge, not too many evangelicals come out of Cuba, OK? Just remember that, OK? Just remember," Trump said at a December rally in Iowa.

Cruz frequently jokes that he is Southern Baptist even though his parents' backgrounds are from traditionally Catholic countries.

View some of Trump's recent tweets attacking Cruz below: