Responding to this post—on City Attorney Pete Holmes's analysis of the tunnel cost overruns—Mayor Mike McGinn has published a post on the city's website, saying it remains unclear who would pay extra costs if the deep-bore tunnel runs over budget.

"If we avoid the issue and wait for cost overruns to occur," McGinn writes, "we will be in the worst position of all—an unfinished tunnel, lawyers litigating Seattle’s share of cost overruns, and a state Legislature with the undeniable power to enforce its spending cap."

The state has pledged up to $2.8 billion toward the project. “The cap on the state’s contributions is quite enforceable. It is essentially carved in stone,” Holmes said in the post yesterday. In addition, state Attorney General Rob McKenna told KUOW last fall, “It’s really going to come down to whether or not the Legislature wants to try and hold Seattle’s feet to the fire and they don’t do that through a law, they do that through the state transportation budget."

McGinn argues that Seattle must establish a plan "before we enter into a final agreement with the state. We have a path to negotiate now for an agreement that protects Seattle from cost overruns."