Minnesota senators approved a multibillion-dollar transportation package Monday, but not before transit funding provoked a fight between the east and west halves of the Twin Cities metro.

At issue: longstanding gripes from east-metro lawmakers that Minneapolis and the west metro are getting the benefit of more major transit projects.

“The transit lines that have been funded or are in complete or in preliminary engineering are … on the left side of the map,” Sen. Bev Scalze, DFL-Little Canada, told her fellow senators, referring to a map of Metro Transit transitways. “The dotted lines on the right side of the map are the east-metro lines that are not yet complete.”

State Sen. Scott Dibble, DFL-Minneapolis, and the head of the Senate’s transportation committee, acknowledged that treating “the east side equitably” has been “the source of a lot of anxiety.”

Dibble was one of a handful of west-metro senators to back Scalze’s proposal that the Metropolitan Council attempt to spend 40 percent of its transit sales-tax revenue in the east metro, “where 40 percent of the people reside.”

That proposal provoked a strong pushback from west-metro lawmakers, led by Sen. Terri Bonoff, DFL-Minnetonka, and Sen. Ron Latz, DFL-St. Louis Park.

“If Hennepin County’s doing the heavy lifting here in terms of putting money into the system, it seems to me fair that Hennepin County reaps its proportional benefit,” Latz said.

He supported an amendment to give Hennepin County a bigger share of taxes from leased vehicles. The formula devised by Dibble divided that lease revenue among metro counties based on their population but treated Ramsey County as 50 percent of its population and Hennepin County as 25 percent of its population to preserve more money for the less populous metro counties.

Latz and Bonoff suggested crediting Hennepin County with 50 percent of its population.

But majorities of the Senate approved the 40 percent goal for the east metro and rejected a higher share for Hennepin County. The voting broke down along geographic lines with almost all east-metro and west-metro lawmakers voting as blocs, regardless of party. But the decisive vote came from outstate senators, who disproportionately sided with the east metro.

All of these metro-dividing fights took place over clauses in the Senate’s transportation package, which raises more than $10 billion over the next decade for roads, bridges and mass transit. The money comes primarily from new taxes on gasoline and motor vehicles, as well as a sales tax in the metro area to fund mass transit.

The overall transportation package passed the DFL-controlled Senate 36-27. But it’s headed for uncertain negotiations with the Republican House, which approved a very different transportation plan.

The House plan also spends billions on transportation over the next decade, though several billion less than the Senate. The Republican-backed bill avoids any tax increases and instead redirects money from the state’s general fund to pay for roads and bridges. It includes much less money for metro mass transit.

Tensions are running high over the issue, which both parties have said is a priority.

Sen. Julianne Ortman, R-Chanhassen, called the Senate DFL plan “a declaration of war on drivers, on car owners” for its tax increases, while Dibble said the bill was in fact “a war on potholes.”

Representatives of the House and Senate now must meet to try to negotiate compromise legislation in the final weeks of the legislative session.

David Montgomery can be reached at 651-224-5064. Follow him at twitter.com/dhmontgomery.