A Dayton administration plan to increase sales taxes for transit would be mandatory in Twin Cities counties and would shift more of the burden of building the Southwest Corridor light-rail line from the state to metro residents.

Details of the proposal drew attention Tuesday as Twin Cities mayors appeared at the Capitol and endorsed the tax to finance more transit lines.

“We have a great plan on the table,” said Minneapolis Mayor R.T. Rybak. “You can’t grow a region if you are stuck in gridlock.”

The proposed quarter-cent sales tax would raise the total Twin Cities transit sales tax to a half-cent. But unlike the current transit tax, the additional fee would become effective without approval of metro area county boards.

The mayors said the larger revenue stream is needed for the Twin Cities to compete with other major metro areas for businesses and jobs.

“Regions around the country are investing far more in the kind of transportation ... that grows jobs,” Rybak said, citing Denver, Seattle and San Francisco.

Republican legislators have been skeptical of the Southwest Corridor and increasing the transit tax. Rep. Mike Beard, R-Shakopee, opposes expanding the tax to Carver and Scott counties, which rejected the current transit sales tax levied in Hennepin, Ramsey, Anoka, Washington and Dakota counties.

However, the officials supporting the Dayton proposal Tuesday at the Capitol included Mayor Brad Tabke of Shakopee, in Scott County, who said the funding would build projects benefiting his community. “We need bold action on transit,” he said.

Other supporters at the Capitol included St. Paul Mayor Chris Coleman, Edina Mayor Jim Hovland and West St. Paul Mayor John Zanmiller.

$110 million to $250 million

Proponents say the additional quarter-cent transit tax would raise $250 million a year. But that figure assumes that Dayton’s plan to expand the broader sales tax is approved. If not, the additional transit tax likely would raise $110 million a year, according to a House fiscal analyst.

Metropolitan Council chair Susan Haigh said Tuesday that the funding could help finance 20 bus-rapid transit lines as well as light-rail operations.

Proponents also said the local sales tax revenue would pick up the state’s $118 million share of the construction costs of the Southwest Corridor between downtown Minneapolis and Eden Prairie.

That marks a change in policy. The state was expected to pay 10 percent — or $125 million — of the cost of building Southwest.

Haigh said the burden of the tax would be spread beyond the seven counties because of the attraction of Twin Cities businesses. Citing retail outlets like the Mall of America, she said, “People are coming from all over ... to pay that sales tax.”