Oregon Senator Jeff Merkley was among the community leaders participating in the first Summer of Love campaign event.

The campaign is part of the effort to repeal Oregon's 2004 voter-approved constitutional amendment which limits marriage to heterosexual couples. Marriage equality advocates hope to put the issue before voters in 2014.

Merkley was joined by several hundred volunteers at the event held in the basement of Sunnyside Church in Portland.

Merkley told Oregon Public Radio that the state's civil rights laws were lacking.

“But that framework is incomplete until we allow the full rights of marriage for all our citizens,” Mekley said.

In addition to Merkley, Rev. Chuck Currie, retired Lt. Col. Linda Campbell and Oregon United for Marriage chief petitioner Jeana Frazzini spoke at the event.

Opponents said they are preparing to defend the amendment.

“This isn't about restricting or trying to keep other people out of it,” said Teresa Harke, spokeswoman for Protect Marriage Oregon, which opposes marriage equality. “It's about respecting what marriage is – a separate union that deserves its own name.”