TALLAHASSEE -- A last-minute proposal this week by Florida Power & Light to settle its rate increase request by offering incentives for the state’s largest power users was slammed Thursday by the state’s top consumer advocate who warned that it will increase costs to most customers.

Reaction has been blistering to the last minute move by Florida Power & Light to settle its $690 million rate case by offering to cut the cost $138 million next year.

The state’s largest utility offered up the deal late Wednesday after reaching an agreement with the state’s largest commercial utility users just days before it is expected to begin a rate hearing on Monday, but the lawyers representing all ratepayers said the offer is worse for residential customers than the company’s original plan.

"We just flat out don’t think it’s a good deal for customers,’’ said J.R. Kelly, director of the Office of Public Counsel on Thursday. He said the proposal shifts $50 million of utility costs from the large utility users, hospitals and military bases who agreed to the deal and puts it onto residential customers and small businesses.

The proposal also would raise late fees $10 million a year "and that goes on the backs of people who can least afford it," Kelly said. It also gives FPL $1 billion in additional rate hikes through 2016, more than the original rate case, he said, to pay for new power plants. News reports that the settlement would reduce the rate case to $358 million next year "are absolutely wrong,’’ Kelly said.

FPL argues that it needs to charge customers more as it moves forward with plans to build new power plants in Cape Canaveral, Rivera Beach and Port Everglades. The company contends that savings from fuel will offset most of the increased costs to consumers.

Kelly, instead, argues that FPL is making excessive profits, using its utility monopoly to subsidize shareholder earnings for the non-regulated side of its business at its parent company, NextEra, and cannot justify the rate increase. He is asking regulators to reject FPL’s rate case request and instead lower customer bills by about $250 million a year.

"We won’t sign it,’’ Kelly said of the settlement offer. His office agreed to a less generous settlement sought by FPL two years ago. "I’m asking myself if I went through the rate case and lost everything, they would get $690 million. Why would I want to sign this and given them $1 billion?"

Signing on to the proposed agreement was the Florida Industrial Power Users Group, which represents large companies and has been one of the most vocal opponents of the rate increases of the past, the South Florida Hospital and Healthcare Association and the Federal Executive Agencies. They praised the proposal as a way to offer stability during a tough economy.

"This agreement will provide Florida’s largest industrial and commercial customers with predictable rates for the next four years, something that is important as the Florida economy emerges from the Great Recession,’’ said Jon Moyle, lawyer for the large utility users.

Linda Quick of the hospital association commended the agreement because it "helps secure low rates for four years" and will provide "rate stability despite an uncertain economy."

FPL President Eric Silagy touted the company’s current bill as justification for allowing the increases to go forward.