A visibly angry Dr. Mehmet Oz went on the attack Thursday, taking on a number of the 10 doctors who demanded that Columbia University fire him as nothing more than shills for powerful food industry interests.

“We will not be silenced,” said the 54-year-old Oz on his nationally syndicated, “ The Dr. Oz Show .”

He accused the 10 as backing the The Safe and Accurate Food Labeling Act of 2014 , which would trump state efforts to increase labeling of genetically-modified food, Politico has reported.

Oz said the federal bill would “make it virtually impossible to mandate labelling.”

"I have never judged GMO foods, but, just like 64 countries around the world, I support GMO labeling so you can decide on the foods for your family," said Oz, whose 1000th show airs May 7.

Oz also said his petition efforts against a super pesticide called Glyphosate has lined up powerful enemies.

Columbia has tread lightly -- so far -- in the unfolding controversy and on the demand that Oz be booted from his post as vice chairman of its College of Physicians and Surgeons.

In a statement, the school said it “is committed to the principle of academic freedom and to upholding faculty members’ freedom of expression for statements they make in public discussion.”

The letter by 10 doctors , none of whom are affiliated with Columbia, said the group is "surprised and dismayed" that Oz is on faculty.

The lead sender is Dr. Henry Miller, a fellow in scientific philosophy and public policy at the conservative Hoover Institute think tank.

It accused Oz of what they call "manifesting an egregious lack of integrity by promoting quack treatments and cures in the interest of personal financial gain."

In a letter Thursday to Time before his show, Oz said Miller is a major friend of Big Tobacco.

And another of enemy signees, Gilbert Ross, was found guilty after trial of 13 counts of fraud related to Medicaid .

Oz wrote: “He (Ross) is now executive director of American Council on Science and Health, a group that has reportedly received donations from big tobacco and food and agribusiness companies, among others . Another four of the 10 authors are also linked to this organization.”

“Freedom of speech is a major right in America and they are trying to silence us and we won’t let that happen,” Oz said at the end of his show.