Ninety-eight House Democrats led by Massachusetts Representative Joseph Kennedy III are calling on President Donald Trump to drop a plan to define gender by a person's genitalia at birth.

Such a move would have the chilling effect of excluding transgender people from protections in existing federal civil rights law.

(Related: Trump proposed rule change would “define transgender out of existence.”)

According to The New York Times, which broke the story, the Department of Health & Human Services (HHS) is leading the effort to define “sex” under federal non-discrimination laws to exclude transgender people.

“We write to you to express our strong objections to reported efforts within your department to eliminate the rights and protections of transgender Americans,” the lawmakers wrote in a letter to HHS Secretary Alex Azar. “The proposal to redefine the definition of 'sex' under Title IX to specifically exclude transgender people is a brazen and targeted attack on the lives of 2 million Americans, effectively abandoning their right to equal access to health care, housing, education and fair treatment under the law.”

“Adoption of this cruel and unscientific definition of sex would undermine enforcement of civil rights for millions, and we implore you to stop any attempt by extremists within the Department of Health & Human Services to infringe upon the dignity, rights and lives of transgender people.”

“Under this proposal, it is possible for a transgender person to be denied access to medical care or health insurance or be refused access to emergency shelter or public housing, and transgender children could be denied access to public education. This leaked proposal makes it clear members of this administration are willing to disregard the established medical and legal view of transgender rights and lives to solidify an archaic, dogmatic and alarming view of the world,” the lawmakers added.

(Related: Google, Facebook, Amazon, Uber denounce Trump's plan to end transgender recognition.)

Out members of Congress who signed on to the letter include Representatives Jared Polis of Colorado, David Cicilline of Rhode Island, Mark Takano of California, Sean Patrick Maloney of New York and Mark Pocan of Wisconsin. Representatives Jackie Speier of California, Ted Lieu of California and Jerrold Nadler of New York also signed the letter.

In a statement given to the Washington Blade, an HHS spokesperson said that it was bound to act by a court ruling which found that the law did not protect people who are transgender. The department did not mention that other cases have found that transgender people are protected under the law.

“We do not comment on alleged, leaked documents that purport to indicate the status of deliberations or the focus of the department,” HHS spokesperson Caitlin Oakley said. “The Obama administration’s broad definition of ‘sex’ was enjoined by a federal court on a nationwide basis in December 2016 and the Obama administration did not appeal. That court found that the Obama administration regulation was overbroad and inconsistent with the text of the 1972 Title IX law prohibiting discrimination on the basis of sex. The court order remains in full force and effect today and HHS is bound by it as we continue to review the issue. Everyone deserves to be treated with respect and HHS’s Office for Civil Rights will continue to vigorously enforce all laws as written and passed by Congress, prohibiting discrimination in healthcare on the basis of race, color, religion, national origin, sex, age, and disability.”

Jon Davidson, legal director at Freedom for All Americans, disputed the claim that the Obama administration did not appeal the ruling and that it remains in force.

“The same day that the Fifth Circuit dismissed the appeal, the plaintiff states that filed the Texas v. U.S. case dismissed their case because the Trump administration withdrew the Obama administration policy and guidance that the states were suing over,” Davidson said. “As expressly stated in the Notice of Voluntary Dismissal filed by the plaintiff states this dismissal ‘necessarily dissolved’ the preliminary injunction, which is no longer in effect.”