Sen. Tom Bakk, DFL-Cook, and Gov. Mark Dayton, right, talked with reporters, May 1, 2015. Tom Scheck | MPR News

Gov. Mark Dayton tried again Wednesday to reach an agreement on a special session with Republican House Speaker Kurt Daudt.

But the disagreements Dayton has with Republicans, particularly on education spending, are just some of his challenges.

Perhaps almost as difficult for Dayton will be negotiating the differences between Democrats who disagree on big issues in the bills he vetoed, including education, economic development and the environment. They expose an urban-rural divide in his party.

Dayton said this week that his toughest veto was the spending bill for agriculture, environment and natural resources.

Although the bill included money for avian flu relief and a compromise on the buffer strips that he wants between farm fields and bodies of water, the governor said there were too many bad policy provisions in the bill. He blamed the DFL-controlled Senate, not the Republican-controlled House.

"There were just some really egregious anti-environment positions in the final bill," Dayton said. "Frankly, probably more of them emanated from the Senate than they did from the House, and I was very unhappy with that."

Dayton's list of objections included the elimination of the Minnesota Pollution Control Agency's citizen review board, added rule-making steps for the agency, cuts to two landfill accounts and amnesty for polluters that self-report violations.

Similar concerns were raised about the bill in the Minnesota Senate during the closing hours of the regular session.

State Sen. Chris Eaton, DFL-Brooklyn Center, noted a "surprise" addition to exempt sulfide mining from solid waste rules.

"It was never introduced as a bill or heard in any committee, and its future effect is unknown," Eaton said. "These are important serious issues, and they should be vetted through committees, not just added in the dark of night."

The bill would put air, water and land at risk, said state Sen. Scott Dibble, DFL-Minneapolis.

"These aren't private sewers that people can simply dump their own poisons and toxins into," Dibble said. "These are the things we all rely on for our life, for our economy, for our health."

Ten Democrats, nearly all from rural districts, joined Republicans to pass the bill, 35 to 30. There were 29 Senate Democrats, including Eaton and Dibble, who voted against it.

Some Democrats also voted against the E-12 education bill and the jobs and energy bill on the final day. Dayton vetoed those funding measures too.

Disagreements among Democrats could get in the way of a deal for the special session, said State Rep. Pat Garofalo, R-Farmington, the House negotiator on the jobs and energy bill.

"The big fight is not between Republicans and Democrats. It's between the urban Democrats and the rural Democrats," Garofalo said. "We can negotiate with the rural Democrats. That's not a problem. We've demonstrated that. We've passed our bills. It's the urban Democrats that are causing problems."

The top Democrat in the Senate downplayed the divide.

Senate Majority Leader Tom Bakk said coalitions based on geography are nothing new at the Capitol. He said there are often big differences in the needs of rural and metro areas, especially when it comes to issues like education and economic development.

"This whole metropolitan area is [where] the economy is doing very, very well," said Bakk, DFL-Cook. "Unemployment is as close to zero as you're going to get it. You get into rural areas and members are really frustrated because their communities are really struggling. We're not trying to figure out how to build new schools. We're trying to figure out how to keep schools from closing and further consolidation. Schools are part of the identity of a community."

Bakk said he had not yet talked with many DFL caucus members since the end of the regular session. But he said he understands their disappointment with some of the compromises he struck with the House.

The special session, Bakk said, provides an opportunity to try to improve three of those bills.