Katherine Jackson is currently on her way back home to Calabasas from her vacation with family in Arizona.

The 82-year-old Jackson matriarch is aware of TJ Jackson's (Tito's son) move to take over as temporary guardian of Michael's three kids ... Paris, Prince and Blanket.

We've learned Katherine Jackson spoke to TJ last night.

Our Jackson family source tells us that TJ asked Katherine if he could take over as legal guardian. We've learned exclusively that Mrs. Jackson told TJ specifically:

    "I don't give you authority to become temporary guardian of the children. It's not going to happen. I'm coming home tomorrow."

Of course "tomorrow" is now today. Our source adds:

    "This is a conspiracy to take the children from Katherine Jackson. The executors, John McClain and John Branca, are instructing TJ what to do."

John Branca, co-executor of Michael's estate, has released the following statement:

    "We are concerned that we do what we can to protect them from undue influences, bullying, greed, and other unfortunate circumstances."

Katherine is currently en route from Arizona to Calabasas.

ABC News will soon be releasing video of Katherine.