Disgraced city Councilman Larry Seabrook’s mistress is set to spill the beans on his alleged control of the non-profits he showered with more than $1 million in council “slush” funds.

Prosecutors revealed yesterday that Gloria Jones-Grant — who had a relationship with the Bronx Democrat from 2004 to 2007 — has been given immunity to testify at his upcoming corruption trial.

bruce.golding@nypost.com