The Democratic Party Sunday voted to include a pro-gay marriage plank in their convention platform for the first time in history, party sources confirm.

The language was approved unanimously by the 15-member platform draft committee and now heads for approval by the full platform committee in August.

Newly-wed Rep. Barney Frank (D-Mass) sits on the Democratic platform draft committee.

This follows the early July announcement that members of the Platform Drafting Committee, which include openly-gay (and newly-wed) Rep. Barney Frank (D-MA) that such a plank was in the offing.

Other Committee members are former U.S. Representative Tony Coelho, Tino Cuellar, U.S. Representative Barney Frank, Donna Harris-Aikens, Colin Kahl, Nancy Keenan, Heather Kendall Miller, Thea Lee, U.S. Representative Barbara Lee, Susan Ness, Mayor Michael Nutter, Carlos Odio, former U.S. Representative Robert Wexler and Christen Young. Serving as ex-officio members are Governor Deval Patrick, DNC Secretary Alice Germond, and Tom Wheeler. The Platform Drafting Committee will be chaired by former Governor Ted Strickland of Ohio.

Congressional 28^th district Representative (and likely to be 29^th district Rep., representing West Hollywood) Adam Schiff – who desires to lead on LGBT equality - organized the entire California Democratic Congressional Delegation to support a marriage equality plank.

Rep Adam Schiff will likely soon represent West Hollywood, and has said he wishes to lead on Marriage Equality in the House. Photo by WeHo News.

Joining Rep. Schiff in signing onto the letter are Reps. Lois Capps, Zoe Lofgren, Lucille Roybal-Allard, Lynn Woolsey, Mike Thompson, Anna Eshoo, Jackie Speier, Susan Davis, Janice Hahn, Judy Chu, Grace Napolitano, Howard Berman, George Miller, Linda Sanchez, Loretta Sanchez, Xavier Becerra, Henry Waxman, Sam Farr,  Pete Stark, Mike Honda, Doris Matsui, Jerry McNerney, Brad Sherman, Karen Bass, Maxine Waters, Joe Baca and Bob Filner. 

Democratic Leader Nancy Pelosi, Sen. Dianne Feinstein and Sen. Barbara Boxer had previously signed. 

The full letter is below:

To the Members of the Democratic Party Platform Drafting Committee:

The Democratic Party has a noble history of fighting for the human and civil rights of all Americans.

We, the undersigned, believe it is time for the Party to hold true to this record and add to the legacy by taking a stand in support of the freedom to marry for all loving and committed couples.

We urge you to affirm the freedom to marry in the Democratic Party by including this plank in the platform discussion of families:

The Democratic Party supports the full inclusion of all families in the life of our nation, with equal respect, responsibility, and protection under the law, including the freedom to marry. Government has no business putting barriers in the path of people seeking to care for their family members, particularly in challenging economic times. We support the Respect for Marriage Act and the overturning of the federal so-called "Defense of Marriage Act," and oppose discriminatory constitutional amendments and other attempts to deny the freedom to marry to loving and committed same-sex couples.

Numerous national polls have shown that a majority of Americans support marriage for same-sex couples. And Democrats overwhelmingly support the freedom to marry, with polls showing as much as 70% support. You are uniquely positioned to stand with the majority of Americans, and the super-majority of the party, and help make a real difference for families across the country.

In May, President Obama came out for Marriage Equality.

We hope the Drafting Committee will fulfill its responsibility to uphold the Party's proud commitment to liberty, equality, and justice for all.

Thank you for helping to put an end to marriage discrimination in this country.

Additionally, Rep. Schiff joined in filing an Amicus Brief in the case of in the case of Karen Golinski v. Office of Personnel Management.

This landmark case follows the 1st U.S. Circuit Court of Appeals in Boston’s ruling that Section 3 of the so-called Defense of Marriage Act (DOMA) is unconstitutional.

Last year, President Barack Obama and Attorney General Eric Holder reached the same conclusion and announced that the Department of Justice would no longer defend the law in certain court cases.

In response, in March of 2011, Speaker John Boehner convened the House of Representative’s Bipartisan Legal Advisory Group (BLAG), which voted (3-2) to proceed with hiring outside lawyers to defend DOMA in court at considerable taxpayer expense.

“The United States Department of Justice no longer defends this law, the House’s own ‘Bipartisan Legal Advisory Group’ is losing the court battle, and at a time of very limited resources, it is impossible to justify spending money defending an unconstitutional law,” said Rep. Schiff.

“Rather than throwing good money after bad, I believe we should accept what is plainly apparent, that DOMA unconstitutionally discriminates against a particular class of Americans, and should be struck down by the courts. Either the House can stand in the way of history, or we can jointly recognize the fundamental right of every American to love, and marry whom they choose.”

The Members’ brief, available here, provides a comprehensive explanation of how Section 3 of DOMA undermines Congress’s legitimate interests.

A total of 130 Members have joined the amicus filing.