The Catholic Archdiocese of Seattle will support the effort to repeal gay marriage in Washington state.

Archbishop J. Peter Sartain and Auxiliary Bishop Eusebio Elizondo said in a letter to the faithful that the diocese would help collect signatures for Referendum 74, the Seattle Post-Intelligencer reported.

The officials argued that denying marriage to gay and lesbian couples is not tantamount to discrimination.

“Treating different things differently is not unjust discrimination. Marriage can only be between a man and a woman because of its unique ends, purpose and place in society. The word 'marriage' isn't simply a label that can be attached to different types of relationships.”

“Instead 'marriage' reflects a deep reality – the reality of the unique, fruitful, lifelong union that is only possible between a man and a woman. There is nothing else like it, and it can't be defined or made into something that it isn't”

Democratic state Senator Ed Murray, a Catholic and a primary sponsor of the law, called the move “fairly reprehensible.”

“As a gay person, and a Catholic, I can understand their refusal to perform [gay] marriages,” Murray told the paper. “Using the church in promoting a referendum … is very disappointing.”

Washington's gay marriage law was signed by Governor Chris Gregoire in February. Gay and lesbian couples may wed in the state starting on June 7. That is, provided opponents do not gather sufficient signatures to put Referendum 74 on the ballot, in which case marriage equality would be put on hold pending the outcome of a November election.

(Related: Washington Archbishop Peter Sartain testifies against gay marriage bill.)