As Cook County commissioners are set to vote to repeal a tax on sweetened beverages on Tuesday, a new poll finds that the millions of dollars in ads spent by former New York City Mayor Michael Bloomberg may not have done much to sway public opinion.

A poll of 1,050 registered voters taken on Oct. 6 and Oct. 7 found nearly 86 percent opposing the tax. Pollsters asked the same question in early August, with almost 87 percent opposing the tax then — a statistically insignificant change.

Voters were also asked whether they were less likely to vote for a pro-tax Cook County commissioner. In the latest poll, about 79 percent said they would not support a commissioner for re-election should they support the tax. In August, about 83 percent of those polled said they were less likely to vote for them.

Motivations for the tax were also used in poll questioning. Nearly 77 percent of those polled said they believed the tax was in order to raise money, with 11.71 percent saying it was intended to “improve health.” In August, about 80 percent of those polled said they believed commissioners passed the tax to raise funds and not for health reasons.

Bloomberg has spent $5 million on ads supporting the Cook County sweetened beverage tax — citing the health benefits of fewer pop sales. The ads are still running on some major TV networks in Chicago, despite commissioners last week announcing they had enough votes for a repeal which would go into effect in December.

A deal came together last week to end the penny-per-ounce tax on pop and other sugary drinks. The veto-proof deal is a major setback to Cook County Board President Toni Preckwinkle, who said the revenue from the tax was needed to avoid major cuts to public health and safety sectors. Commissioners will have to fill a roughly $200 million budget hole, and Preckwinkle has said there could be an 11 percent cut across-the-board if the tax was repealed.

The polls were conducted by We Ask America, a subsidiary of the Illinois Manufacturers Association — and the IMA is an ally of the tax’s main opponent, the Illinois Retail Merchants Association. The margin of error was plus or minus 3.02 percent.