By Jon Keller, WBZ-TVBy Jon Keller

BOSTON (CBS) – “We’re encouraged by the positive momentum,” says Boston2024 spokeswoman Nikko Mendoza of the new WBUR/MassInc poll that found support for a Boston Olympics at 42%, up from 39% last month.

But if that result – well within the survey’s 4.4% margin of error – constitutes “momentum,” I’d hate to see what “nomentum” looks like.

READ MORE: Gov. Charlie Baker To Make Announcement About COVID Testing And Schools

From day one, Boston2024 and their chief political ally, Boston Mayor Marty Walsh, have insisted that outside of federal security funds and public investment in infrastructure improvements that would outlive the Games, the bulk of the Olympic tab would be picked up by the private sector.

“We are not at all going to use taxpayer funds for the construction of venues or the operation of the games, we remain committed to that,” Mendoza tells WBZ News.

But in the new poll, only 18% say they believe that claim, while a whopping 75% expect taxpayer funds to be used – a deal-breaker for most.

READ MORE: Moderna Plans To Have Combination COVID Booster, Flu Vaccine Ready By Fall 2023

“I think that we have some work to do in educating the public about what our budget looks like, what our revenue projections are,” responds Mendoza. “It’s a lot of information for folks to digest.”

And Walsh? “I think that tells me there’s still an uncertainty out there,” he says.

“Doesn’t it show they don’t believe you or Boston2024 when you swear that won’t happen?” we asked?

“No, I wouldn’t say that because there is going to be public funds used in the infrastructure, and I think that’s been made clear as well,” Walsh replied.

MORE NEWS: Registration For Pan-Mass Challenge Opens Tuesday

But according to Boston City Councillor Josh Zakim, an Olympic skeptic, who will pay remains “the number one concern I keep hearing.” And even though the Olympic boosters claim their June 29 roll-out of a revised budget plan was a model of transparency, when we asked Zakim if the poll shows the public doesn’t find their claims credible, he said: “I’m gonna let them present their plan on the finances.”

Jon Keller