The National Organization for Marriage (NOM) is organizing four rallies to coincide with New York's first gay and lesbian weddings on Sunday, July 24.

The nation's most vociferous opponent of giving gay couples the right to marry has already pledged $2 million to oust the four GOP senators who voted for the legislation establishing marriage equality in the state. The group has also announced a four-year plan to reverse the law, which includes growing a majority in the Legislature to approve a constitutional amendment for the 2015 ballot.

While most city clerk's offices will begin issuing marriage licenses on Monday, several cities, including New York City, have announced they'll open on Sunday, the first day the law takes effect, and fast-track the applications. New York City Mayor Michael Bloomberg will also officiate over the wedding of two of his top staffers at Gracie Mansion on the law's first day.

“I've got really exciting news to announce to you this week: a new coalition, a new plan, a rebuilt PAC. And here's the most exciting news: a huge multi-city series of rallies and protest marches taking place across the state of New York to win a vote to protect marriage in New York's constitution,” wrote NOM President Brian Brown at the group's blog.

NOM is organizing rallies in Manhattan, Rochester, Albany and Buffalo.

The group has previously successfully campaigned against gay marriage laws in California and Maine. But in both instances putting a ballot question before the voters didn't require Legislative approval, a significant barrier in New York.