If the court grants the injunction, it could wreak havoc for the 83 insurance companies that administer the National Flood Insurance Program through the Write-Your-Own system, and for the contractor that runs NFIP-direct, a Federal Emergency Management Agency-administered program for the approximately 833,000 ratepayers who deal with FEMA directly.

It could also impact mortgage services of homes that either are required to have flood insurance on their homes or businesses, or do so voluntarily.

The flood insurance program serves approximately 5.6 million ratepayers nationwide.

The suit said rate hikes scheduled to go into effect are “perceived as an oncoming economic disaster to Mississippi citizens and other persons having homes or businesses located in a flood zone.”

The suit also said that there are bills proposed in Congress that would roll back the premiums or lengthen the time policyholders would have to move to full risk premium rates, but that, “it is unlikely that Congress will act in time to avoid substantial rate increases scheduled by the Federal Emergency Management Agency for implementation.”

MID claims that under the federal Administrative Procedure Act, a federal court “possesses the authority to compel agency action unlawfully withheld or unreasonably delayed.”

The department alleges FEMA's failure to obtain the various studies and other assistance mandated by law amounts to “an agency action unlawfully withheld or unreasonably delayed,” and therefore subject “to review and remedial action.”

At the same time, the Massachusetts congressional delegation asked in letters to the House and Senate congressional leadership that the rate hikes be delayed for all but second homes until a study mandated by the 2012 law on affordability of flood insurance premiums is completed. The letter also asked that funds needed to complete the study be promptly appropriated. Currently, FEMA must pay for all the studies mandated by the 2012 law, the Biggert-Waters Act, through NFIP premiums.

And, a group based in New Jersey announced rallies protesting the rate hikes will be held Oct. 1 in nine states. These include Louisiana, New Jersey, New York, Massachusetts, Vermont, Hawaii, Florida, Iowa, Georgia and Alabama.

The founder of the group coordinating the protest, George Kasimos, a Realtor based in Newark, N.J., said, “We want to make this a national issue.”

In a statement issued after the lawsuit was filed, Chaney a laundry list of issues should be studied before the rate increases go into effect.

“FEMA said they have no discretion in the implementation of the BW-12 act,” Chaney said. “Common sense needs to prevail.”

“The following things should be considered, “accurate elevation maps; a reasonable way for consumers to challenge maps; a reasonable phase in of actuarially sound rates after the studies are completed; voucher programs; enforcement of building codes for new construction; proper land use; the use of reinsurance; choices in deductibles and separate escrow accounts for premiums that Congress cannot raid.”

At the same time, Senate Democratic leadership officials are telling people clamoring for immediate relief that Congress is unlikely to take up the issue until November. George Kasimos, an organizer of Stop FEMA Now, a multi-state organization formed to block large flood insurance increases, said New York and New Jersey senators have told him they have ruled out attaching a delay provision to the Continuing Resolution the Senate is voting on today, or including a delay in legislation increasing the debt ceiling.