Any Tree Defenders in the house?

There's a campaign near me to protect valuable old trees which are slated for destruction. These trees are on public property and being killed to make way for a parking deck. The misguided decision makers have already made it "legal" for them to do this, and some of us intend to fight.

I would love to hear any stories or tips on how to approach strategies for raising public awareness, staging actions, and the like. Tree sitting is already a given. I think our situation is at the point now where we cannot prevail via the legal system. They're doing the murder by the book. I think the only leverage we have is to turn public sentiment so hard against these actors that the political cost for them is too extreme. And even that's a longshot.

Thanks and much love.

Update: I welcome discussion of all methods and actions! After reflecting further I wanted to say I'm particularly interested in agitprop and messaging strategies. Perhaps this is discussed in the Ecodefense link - will be checking that out shortly.