This story was originally posted yesterday around Noon.

Mayor Mike McGinn said this morning that he would veto city legislation moving forward with construction on the deep-bore tunnel, expected later this month. McGinn said the council should "stand up and say we won't go forward with" the project unless the state legislature reverses a law that puts city taxpayers on the hook for cost overruns on the tunnel.

The city plans to co-sign a request for proposals for tunnel construction with the state at the end of May. A previous memorandum of understanding with the state passed the city council unanimously; unless McGinn manages to convince four council members to change their positions, that's a veto-proof vote.

Speaking to reporters after McGinn's press briefing, council president Richard Conlin excoriated the mayor for "grandstanding" on the tunnel and said he believed the council would vote again to uphold their agreement. "I just don't think he understands the way these processes work," Conlin said.

McGinn "has not done the work he needs to do," Conlin continued. "If he was concerned about the legislation, he would have worked with the legislature... If he was concerned about the project he would have worked collaboratively with the city council."

Noting that 90 percent of megaprojects, historically, have gone over budget, McGinn said that "if we don't speak now, we will be responsible for cost overruns."

"Don't you wish that someone at Washington Mutual had said, 'Maybe we shouldn't make those subprime loans?" McGinn said, gesturing toward a chart showing the relative size of the city's current $56 million budget deficit and a 50 percent tunnel overrun of $1.5 billion. "That's the point we're at now."

The state has included a cushion approximately $450 million in the project for potential overruns.

Asked whether he wasn't also concerned about cost overruns on the seawall project---for which he has proposed a $291 million bond measure---McGinn said, "The seawall might be over budget," but "it's a much simpler engineering project. ... The seawall is a requirement. It holds back Puget Sound up to First Avenue. We don't have an alternative but to replace it."

He added, "Seawalls are known technologies and known construction techniques."