The US state of Florida will file a brief supporting Mississippi’s court appeal against Federal Government increases in flood insurance rates.

Mississippi’s case against the Federal Emergency Management Agency (FEMA) will begin on October 28.

Higher flood cover rates took effect from October 1, as FEMA began to phase out National Flood Insurance Program (NFIP) subsidies.

Florida Governor Rick Scott and Attorney-General Pam Bondi say the state will file a “friend of the court” brief backing Mississippi.

“President [Barack] Obama is failing to save Florida families from huge flood insurance rate rises and that is why we are going to support Mississippi,” Mr Scott said.

“This unfair rate rise could devastate Florida’s real estate market and homeowners.

“Ultimately, the buck stops with the President and that’s why we continue to ask him to get his agency – FEMA – to undo this unfair insurance rate rise on Florida families.”

Mississippi Insurance Commissioner Mike Chaney filed the lawsuit against FEMA last month. He says NFIP remapping has led rates in some coastal areas to soar.

FEMA recently released new flood maps for New York and New Jersey, where shoreline homes face five-fold premium increases.

Nationally, business property owners with subsidised premiums will pay 25% more each year for four years, until their rates reflect the full risk.