Brian Brown, president of the National Organization for Marriage (NOM), on Wednesday criticized Illinois lawmakers for approving a gay marriage bill.

The House approved the marriage bill on Tuesday with one vote to spare, following in the footsteps of the Senate, which approved the bill on Valentine's Day. A change to the law's start date – from January to June – meant a return trip to the Senate. Senate members made quick work of the measure and it was on its way to Governor Pat Quinn's desk within hours after the House voted.

(Related: Illinois Gov. Pat Quinn to sign gay marriage bill this month.)

“It's disappointing but not surprising that the House has voted to redefine marriage,” Brown wrote in a blog post. “The losers will be the people of Illinois who will see that redefining marriage will unleash a torrent of harassment toward those who believe that marriage is the union of one man and one woman.”

“Once the law goes into effect in June next year, we will see individuals, businesses and religious groups sued, fined, brought up on charges of discrimination and punished simply for holding true to the traditional view of marriage,” he said without elaborating.

Brown, who heads the nation's most vociferous group opposed to same-sex marriage, also described the bill's religious exemptions as “not meaningful.”

In an interview with USA Today in March, Brown predicted the bill would fail. He said that the bill's slow progress – it took nearly a year and several attempts to clear both chambers – “shows you that this myth that somehow same-sex marriage is inevitable is just a myth.”