Donald Trump must be feeling the heat of Ted Cruz on his neck because he unleashed a veritable tirade against the Texas senator on Twitter Saturday.

He started just before 8 a.m EST flat-out calling Cruz a Canadian citizen.

Ted Cruz was born in Canada and was a Canadian citizen until 15 months ago. Lawsuits have just been filed with more to follow. I told you so — Donald J. Trump (@realDonaldTrump) January 16, 2016

For the next several hours the Republican presidential front-runner just unloaded with tweet after tweet, most of them coming within minutes of each other.

Ted Cruz said he “didn’t know” that he was a Canadian Citizen. He also FORGOT to file his Goldman Sachs Million $ loan papers.Not believable — Donald J. Trump (@realDonaldTrump) January 16, 2016

Was there another loan that Ted Cruz FORGOT to file. Goldman Sachs owns him, he will do anything they demand. Not much of a reformer! — Donald J. Trump (@realDonaldTrump) January 16, 2016

The Ted Cruz wiseguy apology to the people of New York is a disgrace. Remember, his wife’s employer, and his lender, is located there! — Donald J. Trump (@realDonaldTrump) January 16, 2016

Oh no, just reported that Ted Cruz didn’t report another loan, this one from Citi. Wow, no wonder banks do so well in the U.S. Senate. — Donald J. Trump (@realDonaldTrump) January 16, 2016

Oh no, just reported that Ted Cruz didn’t report another loan, this one from Citi. Wow, no wonder banks do so well in the U.S. Senate. — Donald J. Trump (@realDonaldTrump) January 16, 2016

Based on the fact that Ted Cruz was born in Canada and is therefore a “natural-born Canadian,” did he borrow unreported loans from C banks? — Donald J. Trump (@realDonaldTrump) January 16, 2016

Ted Cruz purposely, and illegally, did not list on his personal disclosure form personally guaranteed loans from banks. They own him! — Donald J. Trump (@realDonaldTrump) January 16, 2016

Syndicated columnist Phil Kerpen corrected him but that wasn’t going to stop Trump.

Might want to actually look at that personal disclosure form. All the loans are there. @realDonaldTrump https://t.co/ptudBHg7ix — Phil Kerpen (@kerpen) January 16, 2016

Ted is the ultimate hypocrite. Says one thing for money, does another for votes. https://t.co/hxdfy0mjVw — Donald J. Trump (@realDonaldTrump) January 16, 2016

Cruz responded to Trump’s rant on Saturday at a church outside of Charlotte where he was making an appearance.

“I would note that Donald’s record does not match what he says as a candidate,” he told reporters according to CNN.

“I imagine it pulled him out of bed this morning and send him tweeting and tweeting and tweeting,” he said. “I think in terms of a commander-in-chief, we ought to have someone who isn’t springing out of bed to tweet in a frantic response to the latest poll.”

Trump, however continued his Twitter attacks.

If Ted Cruz is so opposed to gay marriage, why did he accept money from people who espouse gay marriage? — Donald J. Trump (@realDonaldTrump) January 16, 2016

Including, what might have been his most absurd comment, suggesting that Cruz should be “kicked out of politics.”

Everybody that loves the people of New York, and all they have been thru, should get hypocrites like Ted Cruz out of politics! — Donald J. Trump (@realDonaldTrump) January 16, 2016

But wait there’s more.

When will @TedCruz give all the New York based campaign contributions back to the special interests that control him. — Donald J. Trump (@realDonaldTrump) January 16, 2016

Greatly dishonest of @TedCruz to file a financial disclosure form & not list his lending banks- then pretend he is going to clean up Wall St — Donald J. Trump (@realDonaldTrump) January 16, 2016

Wow! Ted Cruz received $487K in campaign contributions, $11M from a NY hedge fund mogul, & $1M low int. loan from Goldman Sachs. Hypocrite — Donald J. Trump (@realDonaldTrump) January 16, 2016