Gov. Mark Dayton on Friday laid out his demands for a transportation funding package, hoping to jumpstart progress on a deal with Republicans. But lawmakers aren’t close to agreeing and time is running out.

Dayton called for $600 million a year in spending for roads and bridges and $280 million a year for transit, saying anything less would be a disservice to Minnesota. Republican lawmakers, however, remain firmly opposed to the tax increases needed to make that kind of long-range investment.

With only three full weeks left in the 2016 session, lawmakers are still no closer to resolving the transportation funding bill that they couldn’t agree on last year.

Dayton detailed his basic demands in a letter to House Speaker Kurt Daudt, R-Zimmerman, and Senate Majority Leader Tom Bakk, DFL-Cook, saying he was setting a marker for conference committee negotiations expected to gear up next week.

“I’m not going to pretend that anything less than this is adequate,” he told reporters Friday. “I’m going to keep insisting upon an adequate a bill, a bill that’s sufficient. This isn’t the Cadillac model.”

Dayton said he wants all sides to agree on how much money is needed before heading into negotiations. With the amounts settled, talks could then focus on where to get the money, he added.

“I’m then hopeful we can piece together a combination of revenue sources that are real dollars, that are sustainable, that are not going to eviscerate the general fund or other (general obligation) bonding needs,” Dayton said. “If there’s a willingness to work together, I’m willing to work to achieve that goal.”

If there’s no agreement first on the dollar amount, however, he said he’d be very pessimistic about reaching a transportation deal again this year.

Dayton said he believes a variety of funding sources are needed, and he won’t rule out anything. He and Senate Democrats favor a gas tax increase for roads and bridges, and a metro area sales tax increase for transit.

House Republicans oppose a gas tax increase. They want to use existing sales tax revenues, as well as surplus money, and focus solely on funding roads and bridges.

Daudt said he’s optimistic that a deal can be reached, and he welcomed the governor’s willingness to show some flexibility. With the exception of the gas tax, Daudt said he’s also open to considering other possible revenue sources.

“I told him earlier this week that we’d be willing to listen to anything,” Daudt added. “I gave him some ideas that I’m probably not going share with you right now of other ways I think we can close the gap.”

Daudt is upbeat about a funding agreement for roads and bridges but not for transit. He said the proposed sales tax increase for transit remains controversial for House Republicans. They especially oppose any funding for the Southwest Corridor light rail project. Daudt said there are simply no votes in his caucus, though he added that he’s willing to talk.

“We might be open to a referendum type vote to allow for an increase in the sales tax,” Daudt said. “But, at this point, I think we need to see that the dollars are being spent wisely and they fit in as part of a bigger plan. We’ve got some real concerns about the Met Council and how the dollars are being spent now.”

In the earlier news conference, Dayton defended the Southwest light rail plan and transit in general. He said there will be serious consequences if the transit system doesn’t keep pace with population growth projections for the metro region.

“To overload the metropolitan area with 750,000 more people, all using our highways, is madness,” Dayton said. “If we don’t make these decisions now, that’s what we’ll have by default 10 and 20 years from now, and we’ll have a congested gridlock beyond anything we have now.”