Massachusetts Senator Ted Kennedy introduced a federal gay protections bill in the Senate Wednesday that includes transgender protections.

Kennedy was joined by three senators – one Democratic, Jeff Merkley of Oregon, and two Republicans, Olympia Snowe and Susan Collins of Maine – in sponsoring the legislation that would ban employment discrimination on the basis of sexual orientation and gender identity (transgender protections). Massachusetts Representative Barney Frank introduced the House version of the Employment Non-Discrimination Act (ENDA) last month. The bill has attracted thirty four co-sponsors in the Senate.

“The promise of America will never be fulfilled as long as justice is denied to even one among us,” Senator Kennedy said in a statement. “The Employment Non-Discrimination Act brings us closer to fulfilling that promise for gay, lesbian, bisexual and transgender citizens. I'm proud to join Senators Merkley, Collins and Snowe in introducing this important legislation.”

Both versions of the bill have been reworked, adding back transgender protections removed from last year's bill. Gay rights groups warned politicos last year that they would not support a gay-only protections bill.

“I am encouraged,” Frank told gay weekly the Washington Blade about the inclusion of transgender protections in this year's House bill. “I think the transgender community and others have been doing this in a very good way. This time they have been doing the lobbying.”

“Transgender people face tremendous discrimination in the workplace,” said Michael Silverman, executive director of Transgender Legal Defense & Education Fund, a transgender rights group, in a statement. “In these difficult times, it is imperative that Congress pass the Employment Non-Discrimination Act to ensure that transgender people, like all Americans, have an equal opportunity to participate in the workplace.”

Proponents dropped transgender protections from last year's bill only to have the legislation fizzle in the Senate after House approval.

A large majority of Fortune 500 companies protect gay and lesbian workers but only a third include transgender provisions. Transgender people are protected from workplace discrimination in only 12 states.

“This bill will ensure that protections against workplace discrimination are extended to all Americans including the transgender community,” said Mara Keisling, executive director of the National Center for Transgender Equality, in a statement. “There is no reason why people should lose their livelihood because of who they are.”

Transgender protections bills have sparked heated debates in statehouses throughout the country as opponents argue that such laws invite sex offenders to lurk in public restrooms, endangering public safety.

“This is a bill that begins to confuse the gender differences between men and women to the point of trying to allow men to use women's restrooms, and, of course, that means sexual predators going after young children,” Tom Minnery, senior vice president of public policy at Focus on the Family Action, said in a radio message urging North Dakota voters to oppose a transgender protections bill.

Proponents call the argument seriously flawed: “Anyone that uses a facility to commit a crime or does something indecent can be prosecuted under current laws and this bill does nothing to change that,” Massachusetts Representative Carl Sciortino, who is sponsoring a transgender protections bill, told the AP.

Opponents of ENDA argue that the legislation impinges on religious freedoms.

“This bill will mean that employers will be forced to make employment decisions against their religious beliefs, and that is unacceptable in a country that was founded on the freedom of religious expression,” Ashley Home, federal policy analyst for Focus on the Family Action, told Citizen Link.

National civil rights organizations have endorsed the bill, including the Human Rights Campaign, the Leadership Conference on Civil Rights, and the ACLU, as have over 50 Fortune 500 companies.