City Council members Mike O'Brien (left), Sally Cark and Tim Burgess discuss at City Hall a letter sent to developer Chris Hansen Monday saying they want changes to the agreement to build an arena in SoDo. / Art Thiel, Sportspress Northwest

Chris Hansen’s offer for a new sports arena is not good enough, said a letter signed Monday by eight of the nine members of the Seattle City Council. But that doesn’t mean no – more like whoa.

The council members were eager to make clear they weren’t be obstructionist,  just hard negotiators.

“As we move forward to ‘yes,’ we think we can work through these things,” said council member Tim Burgess, who chairs the council’s finance committee overseeing the proposed $490 million project in SoDo. He and fellow council members Sally Clark and Mike O’Brien called a press conference Monday 45 minutes ahead of the scheduled meeting of the King County Council that was to have included later in the day a vote on the memorandum of understanding.

The city council wanted to get out ahead of the county council so it didn’t appear that that the city was trailing the county in hard-balling Hansen into concessions in the original MOU.

Clark emphasized that nothing in the letter was new to Hansen, whose team has been in private negotiations with city and council staff for weeks.

“We know this is deal has been described as the best deal Seattle has received,”  she said. “We want this to be a great deal for everyone.”

Besides seeking more security for the public’s potential $200 million lease-purchase investment and protecting the city-owned KeyArena, the council members (except for Bruce Harrell)  were pushing to get Hansen to agree to divert some portion of the revenue stream dedicated in the MOU to debt retirement to traffic mitigation.

“We are not supportive of a structure that captures 100% of the public resources generated by the arena for private purposes (and) does not represent an appropriate balance between private and public benefit,” the letter said.

The original deal proposes a $200 million “loan” via construction bonds to build an arena once NBA and NHL teams are secured, or $120 million if only the NBA is brought in. Hansen said the deal could work either way, leaving the council to ask that some portion of the difference between the numbers be dedicated to traffic mitigation that would satisify at least some of the complaints by arena opponents.

“We expect that Mr. Hansen will come back to us and say, ‘This can be done,’ or, ‘you’re crazy,” said Clark.

Burgess said that he has he did not think that any of the proposed changes to the MOU would preclude a vote planned for Sept. 20. But changes to the MOU would first have to be approved by another vote from the city council.