UPDATE: 9/20/14 -- Since the publication of this piece, a number of lawmakers have indicated that they back the effort and have signed onto the letter. See the new list here.

WASHINGTON -- Nearly 200 members of the House have signed a letter putting pressure on President Barack Obama to sign an executive order providing workplace protections for lesbian, gay, bisexual and transgender Americans.

"We are writing to urge you to fulfill the promise in your State of the Union address to make this a 'year of action' and build upon the momentum of 2013 by signing an executive order banning federal contractors from engaging in employment discrimination against lesbian, gay, bisexual, and transgender (LGBT) Americans. As you have said before, 'now is the time to end this kind of discrimination, not enable it,'" the letter says.

The effort was organized by Sens. Jeff Merkley (D-Ore.), Tammy Baldwin (D-Wis.) and Tom Harkin (D-Iowa) in the Senate and by the LGBT Equality Caucus in the House.

Obama has the ability to ban only that employment discrimination by government contractors. Congressional legislation would apply to all employers. The proposed Employment Non-Discrimination Act (ENDA), sponsored by Merkley, has passed the Senate, but it doesn't appear to be going anywhere in the House.

"All Americans deserve fairness in the workplace," said Merkley in a statement on Tuesday. "There is no reason to wait any longer to extend non-discrimination policies to federal contractors and protect millions of Americans from being fired for who they are or who they love."

Rep. Lois Capps (D-Calif.), who has been pushing the president to act on a nondiscrimination executive order for years, said, "Many LGBT Americans are less concerned with how these protections are put in place -- whether they come from a bill the President signs into law or an executive order -- they simply want and need protection from workplace discrimination. This is a simple act that can make a tremendous difference in the lives of 16.5 million Americans."

No Republicans signed on to the letter asking Obama to issue an executive order, even though 10 of them voted for ENDA in the Senate and six are co-sponsors of the House legislation. Republicans have been wary of allowing the president to use his authority without going through Congress.

The current letter shows that support for executive action on LGBT discrimination is growing. Last year, lawmakers circulated a similar letter, which had about a dozen fewer backers in the Senate and about 40 fewer in the House.

Sens. Michael Bennet (Colo.), Heidi Heitkamp (N.D.), Joe Manchin (W.Va.), Mark Pryor (Ark.), John Walsh (Mont.) and Harry Reid (Nev.) were the only Democrats who didn't sign the latest letter on the Senate side. Maine Sen. Angus King, an independent who caucuses with the Democrats, also did not sign. More than 50 House Democrats didn't join the effort.

The letter picked up the support of Democratic leaders like House Minority Whip Steny Hoyer (Md.), Assistant House Democratic Leader James Clyburn (S.C.), Democratic Congressional Campaign Committee Chair Steve Israel (N.Y.) and Senate Majority Whip Dick Durbin (Ill.).

In addition to Bennet, chair of the Democratic Senatorial Campaign Committee, other top Democrats not signing the letter included Rep. Debbie Wasserman Schultz (Fla.), chair of the Democratic National Committee, and Rep. Marcia Fudge (Ohio), chair of the Congressional Black Caucus.

Although Reid and House Minority Leader Nancy Pelosi (D-Calif.) were also not signatories, they traditionally don't sign on to these types of letters. Pelosi has said, however, that she supports Obama using his executive authority to extend workplace protections. Reid has said he would support it if the president decided to do it.

The White House has consistently argued that it would like to see Congress pass ENDA, since an executive action wouldn't protect all LGBT workers. Still, an executive order could help as many as 16 million workers, according to a report from UCLA's Williams Institute.

Merkley also has an online petition on CREDO, with more than 45,000 signatories so far saying they would like to see Obama act on this issue.

Senate signatories:

Jeff Merkley (Ore.), Tom Harkin (Iowa), Tammy Baldwin (Wis.), Mark Begich (Alaska), Richard Blumenthal (Conn.), Cory Booker (N.J.), Barbara Boxer (Calif.), Sherrod Brown (Ohio), Maria Cantwell (Wash.), Ben Cardin (Md.), Tom Carper (Del.), Bob Casey (Pa.), Chris Coons (Del.), Joe Donnelly (Ind.), Dick Durbin (Ill.), Dianne Feinstein (Calif.), Al Franken (Minn.), Kirsten Gillibrand (N.Y.), Kay Hagan (N.C.), Martin Heinrich (N.M.), Mazie Hirono (Hawaii), Tim Johnson (S.D.), Tim Kaine (Va.), Amy Klobuchar (Minn.), Mary Landrieu (La.), Patrick Leahy (Vt.), Carl Levin (Mich.), Ed Markey (Mass.), Claire McCaskill (Mo.), Bob Menendez (N.J.), Barbara Mikulski (Md.), Chris Murphy (Conn.), Patty Murray (Wash.), Bill Nelson (Fla.), Jack Reed (R.I.), Jay Rockefeller (W.Va.), Bernie Sanders (I-Vt.), Brian Schatz (Hawaii), Chuck Schumer (N.Y.), Jeanne Shaheen (N.H.), Debbie Stabenow (Mich.), Jon Tester (Mont.), Mark Udall (Colo.), Tom Udall (N.M.), Mark Warner (Va.), Elizabeth Warren (Mass.), Sheldon Whitehouse (R.I.), Ron Wyden (Ore.)

House signatories:

Ron Barber (Ariz.), Karen Bass (Calif.), Joyce Beatty (Ohio), Ami Bera (Calif.), Timothy Bishop (N.Y.), Earl Blumenauer (Ore.), Suzanne Bonamici (Ore.), Robert Brady (Pa.), Bruce Braley (Iowa), Julie Brownley (Calif.), Lois Capps (Calif.), Michael Capuano (Mass.), Tony Cardenas (Calif.), Andre Carson (Ind.), Matt Cartwright (Pa.), Kathy Castor (Fla.), Joaquin Castro (Texas), Judy Chu (Calif.), David Cicilline (R.I.), Katherine Clark (Mass.), Yvette Clarke (N.Y.), James Clyburn (S.C.), Steve Cohen (Tenn.), Gerald Connolly (Va.), John Conyers (Mich.), Joe Courtney (Conn.), Joseph Crowley (N.Y.), Susan Davis (Calif.), Diana DeGette (Colo.), John Delaney (Md.), Rosa DeLauro (Conn.), Suzan DelBene (Wash.), Theodore Deutch (Fla.), Lloyd Doggett (Texas), Michael Doyle (Pa.), Tammy Duckworth (Ill.), Keith Ellison (Minn.), Eliot Engel (N.Y.), Anna Eshoo (Calif.), Elizabeth Esty (Conn.), Sam Farr (Calif.), Chaka Fattah (Pa.), Bill Foster (Ill.), Lois Frankel (Fla.), Joe Garcia (Fla.), Alan Grayson (Fla.), Al Green (Texas), Raul Grijalva (Ariz.), Luis Gutierrez (Ill.), Janice Hahn (Calif.), Colleen Hanabusa (Hawaii), Alcee Hastings (Fla.), Denny Heck (Wash.), Brian Higgins (N.Y.), James Himes (Conn.), Ruben Hinojosa (Texas), Rush Holt (N.J.), Mike Honda (Calif.), Steven Horsford (Nev.), Steny Hoyer (Md.), Jared Huffman (Calif.), Steve Israel (N.Y.), Sheila Jackson Lee (Texas), Eddie Bernice Johnson (Texas), Hank Johnson Jr. (Ga.), William Keating (Mass.), Joseph Kennedy III (Mass.), Dan Kildee (Mich.), Derek Kilmer (Wash.), Ron Kind (Wis.), Ann Kuster (N.H.), James Langevin (R.I.), Rick Larsen (Wash.), John Larson (Conn.), Barbara Lee (Calif.), Sander Levin (Mich.), John Lewis (Ga.), David Loebsack (Iowa), Zoe Lofgren (Calif.), Alan Lowenthal (Calif.), Nita Lowey (N.Y.), Michelle Lujan Grisham (N.M.), Stephen Lynch (Mass.), Dan Maffei (N.Y.), Carolyn Maloney (N.Y.), Sean Patrick Maloney (N.Y.), Jim Matheson (Utah), Betty McCollum (Minn.), Jim McDermott (Wash.), James McGovern (Mass.), Jerry McNerney (Calif.), Gregory Meeks (N.Y.), Grace Meng (N.Y.), Michael Michaud (Maine), George Miller (Calif.), Gwen Moore (Wis.), James Moran (Va.), Patrick Murphy (Fla.), Jerry Nadler (N.Y.), Rick Nolan (Minn.), Eleanor Holmes Norton (D.C.), Beto O'Rourke (Texas), Frank Pallone Jr. (N.J.), Bill Pascrell Jr. (N.J.), Donald Payne Jr. (N.J.), Ed Perlmutter (Colo.), Gary Peters (Mich.), Scott Peters (Calif.), Chellie Pingree (Maine), Mark Pocan (Wis.), Jared Polis (Colo.), David Price (N.C.), Mike Quigley (Ill.), Charlie Rangel (N.Y.), Lucille Roybal-Allard (Calif.), Bobby Rush (Ill.), Linda Sanchez (Calif.), Loretta Sanchez (Calif.), John Sarbanes (Md.), Jan Schakowsky (Ill.), Adam Schiff (Calif.), Brad Schneider (Ill.), Kurt Schrader (Ore.), Allyson Schwartz (Pa.), Bobby Scott (Va.), Jose Serrano (N.Y.), Carol Shea-Porter (N.H.), Brad Sherman (Calif.), Kyrsten Sinema (Ariz.), Albio Sires (N.J.), Louse Slaughter (N.Y.), Adam Smith (Wash.), Jackie Speier (Calif.), Eric Swalwell (Calif.), Mark Takano (Calif.), Mike Thompson (Calif.), John Tierney (Mass.), Dina Titus (Nev.), Paul Tonko (N.Y.), Niki Tsongas (Mass.), Chris Van Hollen (Md.), Juan Vargas (Calif.), Marc Veasey (Texas), Filemon Vela (Texas), Nydia Velazquez (N.Y.), Timothy Walz (Minn.), Henry Waxman (Calif.), Pete Welch (Vt.), Frederica Wilson (Fla.), John Yarmuth (Ky.)

HuffPost Readers: Have you been fired, harassed or discriminated against at work because of your sexual orientation or gender identity? If you're open to sharing your story, please email us at openreporting@huffingtonpost.com, or call us at 860-348-3376 and leave a voicemail describing your experience.

This article has been updated to note that Sen. Maria Cantwell (D-Wash.) and Rep. Chakah Fattah (D-Pa.) have signed the letter. They signed after the article was originally published.