A plan to grant driver's licenses to undocumented aliens is costing Gov. Eliot Spitzer support among New York state voters.

The Siena New York poll, released Monday by Siena Research Institute, shows that Spitzer's job-performance rating is lower than it has ever been, with a majority of voters saying he's doing a fair or poor job. If the 2010 gubernatorial race were held today, SRI said, New York City Mayor Michael Bloomberg, running as a Republican, would beat Spitzer, a Democrat, 50-37 percent.

The poll also found that 72 percent who have read or heard about Spitzer's proposal to allow illegal immigrants to obtain New York driver's licenses oppose the governor's plan, while only 22 percent support it. The majority of respondents cited security as the reason they most oppose the plan.

"The voters' message to the governor is clear: ‘No, no, no.' Opposition to the Spitzer proposal is intense, with 41 percent strongly opposing it and only 7 percent strongly supporting it," said Steven Greenberg, SRI spokesman.

Meanwhile, Spitzer's favorable/unfavorable rating is 54-36 percent, down from 56-26 percent last month and a high of 75-10 percent in January, when he took office. His job-performance rating is 41 percent positive, 55 percent negative, down from 44-49 percent last month and a high of 57-36 percent in May.

"While the governor's numbers may not be falling off a cliff, they are rolling swiftly and solidly downhill," Greenberg said.

In a hypothetical race against Bloomberg for governor in 2010, Spitzer trails 50-37 percent - a reversal from June, when the poll indicated that he would beat Bloomberg 43-41 percent. Democrats favor Spitzer 54-35 percent, while Republicans favor Bloomberg 70-18 percent. Bloomberg leads by 28 points in New York City and 31 points in the downstate suburbs. Spitzer has a 15-point lead over Bloomberg upstate.

On the "troopergate" issue, which involves state Senate Majority Leader Joseph Bruno, nearly 60 percent of New York voters who know about the attorney general's report believe that Spitzer needs to be more forthright about what he knows, while only 29 percent believe he has been honest with the public. Seventy percent of voters continue to believe the governor should publicly testify under oath about everything he knows about the situation.