ST. PAUL — Senate Republicans say they have a plan to fund billions of dollars in road and bridge repairs without raising the gas tax.

Legislation unveiled Monday would tap a mixture of existing taxes on car parts and other automobile expenses, federal grants and borrowing to drum up $3.6 billion over the next decade. But it hinges on future legislators agreeing to the same funding mechanism.

The Legislature has failed for several years to finalize a long-term transportation funding plan. GOP Sen. Scott Newman said it’s time to buckle down to fix basic infrastructure.

Senate Democrats immediately criticized the plan as falling far short of what’s necessary, including its lack of funding for mass transit projects. Minneapolis Sen. Scott Dibble says it doesn’t raise enough revenue to pay for needed projects.