The former couple, who separated in May 2009, are expected to visit London's High Court on Thursday after the 'Mysterious Girl' singer carried out plans to sue his ex-wife for slander and libel.
Andre and Price have failed to fully explain what caused the breakdown of their marriage, hinting in the past that explosive unknown details of their split have yet to be revealed, but the News of the World claims that Andre is now intent on breaking his silence.
"Peter never wanted to have to come to court," an insider said. "Katie's the mother of his children and they were once in love, but he feels that if he doesn't take action, what he considers to be her lies will continue.
"All he wants from her is an undertaking in court that she won't say them again. He has never spilled the beans about what really went on in the final months of their marriage because he doesn't want any of the repercussions to impact on his kids. Katie thinks the case is a waste of time, but Peter's sick and tired of having to worry.
"There'll be a lot of revelations about the end of their marriage. All along Peter has been clear he doesn't want to screw his children's lives up. That's why he's avoided this for such a long time. He's actually had the patience of a saint. But enough is enough."
The source added: "This is going to get very messy and very personal. Peter strongly believes this case needs to be fought in court. He wants the truth to finally come out."
Andre issued the legal challenge last October, following Price's accusations on The Graham Norton Show that he had an affair with his manager Claire Powell, and separate claims in a magazine interview that he was inaccurately portraying his relationship with stepson Harvey.
"Although Peter has no legal right of custody he has always treated Harvey as if he was his own," the insider explained. "Since the divorce he's been desperate to see him regularly. But he'll testify that Katie has made that virtually impossible.
"The courtroom is going to be split in half between the two camps. The atmosphere is going to be absolutely poisonous. All of these people were friends and part of one big family for five years. But since the split they've grown to hate each other. The feelings on both sides are very strong."
