Salt Lake County voters may have thought they killed a $58 million sales tax hike for mass transit and roads when they rejected Proposition 1 back in 2015. But as Dr. Frankenstein proclaimed as lightning bolts revived his cadaverous creation: It’s alive.

The Salt Lake City Council voted 7-0 Tuesday — in the most essential show of support among the valley’s cities — to impose that countywide tax, despite opposition from Mayor Jackie Biskupski and plenty of griping by council members. The tax would add 2.5 cents to a $10 purchase (or 0.25 cents per $1).

The Legislature earlier this year allowed the county to enact the old Proposition 1 tax without direct approval by voters — who earlier torpedoed it largely because of scandals at the Utah Transit Authority (an agency now restructured by lawmakers).

The County Council then voted to give the tax hike decision to cities and townships — which the Salt Lake City Council called a cowardly act, to pass to cities the political heat for approving the tax hike.

The county will impose the tax if it is supported by June 22 by councils representing two-thirds of the county’s population, or 760,885 residents, according to 2017 population estimates used by the county. That would be difficult to achieve without Salt Lake City, which has 200,000 residents.

Before Tuesday, councils representing more than 400,000 residents had supported the measure — Alta, Emigration, Holladay, Kearns, Magna, Midvale, Millcreek, Murray, South Jordan, South Salt Lake, Taylorsville and White City. Cottonwood Heights also endorsed the tax hike on a 5-0 vote late Tuesday.

With 10 days before the county’s deadline, Bluffdale, Draper, Herriman, Riverton, Sandy, West Jordan and West Valley City have yet to vote.

The county would receive all of the revenue for the first nine months of the new tax — but said it would work with cities to approve how and where it is spent. After that, 40 percent of ongoing revenue would go to UTA, 40 percent to cities and 20 percent to the county.

Biskupski tried to persuade the Salt Lake City Council to delay the tax hike, saying this week that “it is not the time” for it — coming after the city just imposed a half-penny-per-dollar sales tax of its own for such things as transit and streets and is asking voters to approve in November an $87 million bond for road reconstruction.

The countywide tax should be “done after public engagement and with strategic plans,” she said, as the city had done for its separate measures but has yet to be done for the countywide tax.

City Council members said much the same thing — but instead supported the tax as needed. “But the timing sucks,” council member Derek Kitchen said.

They also worried the city might otherwise lose power in negotiations on how to spend the tax that members said likely would be imposed on them no matter what they do.

About UTA, for example, council member Charlie Luke said, “I don’t want to say they are vindictive, but their memories are long. ... It will not be lost on them who voted for this and who did not” when deciding where to put new transit routes and projects.

Council member Chris Wharton said cities that do not support the tax hike essentially are telling transportation agencies that they don’t have needs and could be left out.

Council Chairwoman Erin Mendenhall said Salt Lake City’s separate sales tax hike and proposed bond for roads still do not cover all the needs of the city — where two-thirds of its roads have been rated as poor or worse. So she supports the additional countywide tax.

Council member Amy Fowler said her district and most of Salt Lake City actually supported Proposition 1 in 2015. But she’s unsure if they still do because of the city’s other tax hike and proposed bond. She said it’s frustrating not being able to ask if “since we’ve done all these other things to you — are you still OK with this?”

Most members also attacked the county for passing on the political heat to cities instead of simply enacting the tax increase itself.

Member James Rogers said, “I’m still really upset with the County Council. I can’t believe they would thrust this on municipalities. ... It was very cowardly of them to do that.”