Six openly gay Maryland delegates are urging House members to approve a gay marriage bill, The Washington Post reported.

The House could begin debate on the bill as early as Tuesday.

The measure barely stumbled out of the House Judiciary Committee last week after two members altered their votes. Supporters concede they remain a few votes shy of a win.

The gay delegates make their appeal in a letter addressed to colleagues.

A gay marriage law will “secure for our families the protections that marriage – and only marriage – provides to loving and committed couples who have pledged to spend the rest of their lives together.”

Delegate Tiffany Alston last week abruptly pulled her support for the measure and proposed a civil unions amendment to the bill, which was rejected in committee.

“There will also undoubtedly be a debate about whether the state could design some institution other than marriage. We believe that any attempt to create a separate set of rules for our families will be far more complicated than ending the exclusion of our families from marriage and inevitably lead to unequal treatment. … Marriage equality is a far simpler and more powerful solution.”

“Colleagues, we need you,” the letter concludes. “Please vote yes.”

“Vote yes because you know it is the right thing to do. Vote yes because you want to stand on the right side of history. Vote yes because every family in Maryland needs the protections that marriage provides.”

The letter is signed by Democratic Delegates Luke Clippinger, Bonnie Cullison, Anne Kaiser, Maggie McIntosh, Heather R. Mizeur and Mary Washington.

Opponents of gay marriage are widely expected to mount a referendum on the law, if approved by lawmakers.