Republican presidential candidates Donald Trump and Jeb Bush. (AP)

The rivalry between GOP presidential candidates Donald Trump and Jeb Bush has escalated this week, with the latest salvo coming from Bush in a video questioning Trump’s conservative credentials.

In a posting on his campaign website and an accompanying video titled “The Real Donald Trump,” the Bush campaign says Trump’s past statements prove “he is not the conservative he claims to be.” The video depicts Trump interviews and comments over the years, including one where he says he’s “very pro-choice” and another where he offers supportive words for Hillary Clinton.

The Trump campaign had no immediate comment.

On Monday, Trump posted an Instagram video in which he attacked Bush over his 2014 comments on undocumented immigrants in which he said that “yes, they broke the law, but it’s not a felony. It’s an act of love.”

The Trump video shows pictures of undocumented immigrants accused of series crimes, while a video of Bush’s “act of love” comment plays.

Some criticized the video as evocative of the controversial Willie Horton ad run by the George H.W. Bush campaign in 1988.

Bush also hit back at Trump on Monday with a release comparing the billionaire real estate developer’s and the former Florida governor’s record on crime, saying Trump “has spent years supporting soft-on-crime liberals like Harry Reid, Hillary Clinton and Charles Schumer.”

The latest sparring between Bush and Trump comes less than two weeks after the two held competing town halls in New Hampshire, where Trump joked that attendees and Bush’s were likely asleep and Bush again questioned Trump’s conservative bona fides.