The ballot question essentially will ask voters to prohibit the practice of same-sex marriage, which was approved this year by the California Supreme Court.

The discrepancy between voters' general attitudes against gay marriage and their position on banning it could be explained by a hesitancy to remove a constitutional right, said Mark Baldassare, president and chief executive of the Public Policy Institute of California, which conducted the poll.

A majority of likely voters, 54 percent, oppose ending gay marriage, compared with 40 percent who support it, the poll said. The result is similar to the findings of a Field Poll in July, which found that 51 percent of likely California voters opposed ending gay marriage, while 42 percent said they supported it.

But when it comes to general attitudes about gay marriage, voters in the Public Policy Institute poll are evenly split, at 47 percent for and against — as they have been for the past three years.