Look out KATE! Ex-hubby JON GOSSELIN is in super BATTLE ACTION mode!

In a no-hold-barred sit-down, Jon reveals he’s penned a tell-all because he’s broke, has a lousy relationship with his ex while stressing his eight children are the most important part of his new life.

 “I haven’t spoken in four years, so now I’m doing stuff and it is all coming out because I don’t care anymore,” Jon told

“Then it is all going to come out. I’m not bashing her (Kate) but she has got to do what’s right for the kids. You know? When lies come out, I’m going to defend myself. I’ll go to court and tell the judge, here’s the proof, this is what my child wants, and no more B.S. and branding and marketing and product placement. They’re children. The court’s job is to protect the children, not us.”

 “I don’t have fear of my former wife,” he added.

BUT “We still argue about custody.

“I don’t know why she doesn’t want to work together?

“I don’t know what the hate is, what the revenge is? She chose TV, she wanted to get divorced, she marketed the children. I just sit here. I really don’t go out that much.”