Members of the clergy pray before going into a press conference by the Maryland Marriage Alliance during the legislative debate in February over gay nuptials. (Photo by Mark Gail/The Washington Post)

Lori, who leads the nation’s oldest Roman Catholic diocese, is listed atop an invitation for the event sponsored by the Maryland Marriage Alliance, the leading organization opposed to Question 6 on the November ballot.

Several hundred people are expected to attend the gathering at an historic Catholic seminary in Baltimore, but it is closed to both the general public and media, according to a spokeswoman for the Maryland Catholic Conference, a member of the anti-same-sex marriage coalition.

“There’s no glitz or glamor in this event,” said Catholic Conference spokeswoman Kathy Dempsey. “We’re not trying to impress anyone. . . . We just hope this event will energize and organize our faith communities.”

Dempsey was referencing some of the events held by the opposing side.

Marylanders for Marriage Equality recently held a fundraiser in New York featuring a couple dozen actors and other celebrities who support gay marriage. And Adam Lambert, a glam rocker and “American Idol” runner-up, will be featured Tuesday at an event in the District.

Lori was installed as archbishop in May. At the ceremony, he called marriage between a man and a woman “a bedrock institution for the common good of society.”

Also billed to appear at Wednesday night’s event is Derek McCoy, executive director of the Maryland Marriage Alliance.

Gov. Martin O’Malley (D) signed same-sex marriage legislation into law in March, but it was promptly petitioned to the ballot by McCoy’s group. As a result, voters will decide whether gay marriage will go forward in January, as planned under the law.