Same-sex couples can start marrying on Monday across New Jersey, after the state’s Supreme Court denied Gov. Chris Christie’s attempt to block the weddings and suggested that he would have a difficult time winning an appeal of a lower-court ruling that allowed them.

A State Superior Court judge ruled last month that the state had to allow same-sex marriage to comply with two decisions: the United States Supreme Court ruling in June that same-sex married couples have the same rights to federal benefits as heterosexual married couples, and a 2006 ruling by the New Jersey Supreme Court that same-sex couples were entitled to all of the rights and benefits of marriage.

The Superior Court judge, Mary C. Jacobson, ruled that the marriages could begin on Monday.

Mr. Christie’s office appealed the decision, and the state’s Supreme Court has agreed to hear the appeal, with oral arguments scheduled for early January. But on Friday, the court unanimously denied the Christie administration’s request for a stay on marriages until the appeal was settled.

While the court’s ruling on Friday applied only to the request for a stay, it also indicated that the justices did not think the appeal had a “reasonable” likelihood of success.