Sen. Ted Cruz’s (R-TX) presidential campaign is calling on the New York Times to issue a formal apology or release the evidence behind its decision to keep his new book, A Time for Truth, off its bestseller list for what the Times alleges are “strategic bulk purchase,” a practice the Times says violates its methodology for determining “authentic” bestsellers.

“We call on the Times, release your so-called ‘evidence.’ Demonstrate that your charge isn’t simply a naked fabrication, designed to cover up your own partisan agenda,” said Cruz campaign spokesperson Rick Tyler on Friday. “And, if you cannot do so, then issue a public apology to Senator Cruz and Harper Collins editor Adam Bellow for making false charges against them.”

Tyler said the Times’ allegation of “strategic bulk purchases” is “a blatant falsehood.”

The controversy erupted on Thursday when the Times announced its decision to block Republican presidential candidate Sen. Ted Cruz’s (R-TX) new book A Time for Truth from inclusion on the list, despite Cruz’s book outselling 18 of the 20 books that will appear on its July 4 bestseller list.

Politico’s Dylan Byers, who broke the story, says Times spokesperson Eileen Murphy claims the paper’s bestseller list conducts an “analysis of book sales that goes beyond simply the number of books sold” to determine “authentic best sellers” and that Cruz’s book “didn’t meet that standard this week.”

The Times’ spokesperson added, “Our goal is that the list reflect authentic best sellers, so we look at and analyze not just numbers, but patterns of sales for every book.”

A Time for Truth sold 11,854 hardcover copies in its opening week, according to Nielsen Bookscan, an industry-leading standard that captures roughly 70 percent of national sales. The number two book on the Times’ list, Aziz Ansari’s Modern Romance, sold less than 10,000 copies, reports Byers.

Publishing industry insiders confirm that the Times’s highly secretive bestseller methodology does include other variables outside of raw sales—such as consideration of mass or bulk purchases—as part of its calculation. Yet conservative authors say the Times shrouds its formula in secrecy as a way to deny certain authors inclusion on the bestseller list.

The Cruz campaign says “there were no “strategic bulk purchases” and produced pictures from book signings. The campaign also noted that booksellers reported long lines, some with lines numbering over 400 people. Indeed, A Time for Truth ranked as high as #9 on Amazon across all genres.

The Times’ efforts to keep conservative authors off its bestseller list are not new. In 2011, Dick Morris blasted the Times’ for its “ghettoization of the Fox News books,” a tactic he said that placed books by Fox News contributor up against books from unrelated genres.

In Cruz’s case, other bestseller lists, such as the Conservative Book Club and Wall Street Journal bestseller lists, featured A Time for Truth, at the #1 and #4 spots respectively. And the Barnes & Noble bestseller list ranks Cruz’s book as #7.

The Cruz campaign flatly denies the Times’ “strategic bulk purchases” charge and says it is one more example of the liberal media’s efforts to diminish the senator.

“The Times has tried to impugn the integrity of Senator Cruz and of his publisher Harper Collins,” said Tyler.

The Times has yet to issue an apology to Cruz or release evidence to substantiate its charges.