Sixty-three former Roman Catholic priests are expected to announce their support for Referendum 74, the Washington state ballot box question which asks voters to uphold – or reject – a gay marriage law approved by lawmakers.

According to the Seattle Post-Intelligencer, the priests will announce their endorsement at a press conference on Thursday.

The Catholic Church has been vocal in its opposition to passage of the measure.

“Once marriage is redefined as a genderless contract, it will become legally discriminatory for public and private institutions such as schools to promote the unique meaning of marriage,” Bishop Joseph J. Tyson of the Diocese of Yakima wrote.

Last month, J. Peter Sartain, the archbishop of Seattle, warned that society would be harmed “beyond repair” if Referendum 74 was approved. He's also asked parishes to collect donations for the campaign working to defeat the measure. Several parishes have openly refused.

The 63 former priests said the church's aggressive stance against the issue made them “uneasy.”

“We are uneasy with the aggressive efforts of Catholic bishops who oppose R-74 and want to support the 71 percent of Catholics (Public Religion Research Institute) who support civil marriage for gays as a valid Catholic position,” they said in a statement.