Donald Trump reached the peak of his tweetstorm against fellow Republican presidential
hopeful Ted Cruz Friday, threatening to sue the Texas senator over his Canadian birth status.

The billionaire GOP candidate has spent the past 72 hours bashing Cruz on social media, questioning his evangelical beliefs and accusing him of being “crazy” and “very dishonest.” Cruz, over the last few days, has scolded Trump for his use of profane language on the campaign trail and continued to push the narrative that the former Democrat is not a true conservative. Trump’s latest tweet represents the growing tension between the two leading Republican candidates.

Trump’s threat to take legal action to determine whether Cruz is eligible to be president comes less than two months after the brash New York businessman first turned Cruz’s birth status into a line of attack on the campaign trail. He has since recommended that Cruz seek a “declaratory judgement” on the matter, and has repeatedly sparred with the first-term senator over the issue during GOP debates.

Earlier Friday, a report by The Hill claimed that a group of Trump supporters had moved filed a lawsuit in an Alabama district court seeking a judgement “declaring that Rafael Edward Cruz is ineligible to qualify/run/seek and be elected to the office of the president.

Thomas Drake, the attorney representing the Trump fans, said the “only thing they can agree on is Mr. Cruz is not eligible to be president.”

The Cruz campaign could not be reached for comment.