Mississippi-filed lawsuit now seen as last chance to stop January rate hikes.
Measures would delay increases by perhaps four years if they gain passage.
Senate bill would delay NFIP-mandated increases except for second homes and businesses.
State would join Florida, Mississippi in effort to turn back new rates from National Flood Insurance Program.
Federal court plans Oct. 28 hearing in Gulfport on injunction to delay new flood insurance rates.
Injunction sought against FEMA as new rates kick in Tuesday.
State insurance chief says new flood insurance rates will hit middle- and low-income homeowners hard, forcing some to walk away from their homes.
Mississippi insurance commissioner makes that observation, while FEMA says agency continues to eye NFIP privatization.