TALLAHASSEE — It was intended to be an offer the Florida Senate couldn't refuse: Give up the quest to expand Medicaid and the Florida House would set aside $600 million in state money to protect hospitals and county health departments facing extreme budget cuts.But the Senate did refuse the offer late Friday, thrusting the 2015 legislative session into near chaos with just one week to go before its scheduled end.Senate leaders had only a few hours to respond to the House proposal, the latest in a round of offers volleyed between the gridlocked chambers. When they did, they made clear they weren't backing away from their model for Medicaid expansion."The Senate is aware of the House's long-standing opposition to simple Medicaid expansion as contemplated by the (Affordable Care Act)," Senate spokeswoman Katie Betta said in a letter to the House. The Senate proposal "is not the simple Medicaid expansion the House has long opposed. (It) is a new, market-based, consumer-driven alternative with conservative guardrails that will protect Florida taxpayers if the federal government fails to meet its commitments."The back and forth began Thursday when the House said it was willing to use $200 million in state money to help hospitals and health departments that would be hurt by the end of a federal-state program known as the Low Income Pool. The program, which brings $1.3 billion in federal money back to Florida, is set to expire June 30, unless the federal government approves a proposed successor program.The House's first offer would have replaced the LIP program with $200 million that would otherwise be spent on public schools and a proposed tax cut package. House Speaker Steve Crisafulli, R-Merritt Island, said the money could be used to draw down an additional $305 million in federal funds, making $505 million available for hospitals that treat large numbers of uninsured and Medicaid patients.One reason the Senate rejected the offer: The offer did not propose using federal Medicaid expansion money to provide coverage to more than 800,000 low-income Floridians, something the Senate believes would help safety-net hospitals control costs in the long run. "(The House) response indicates their continued unwillingness to deal with insurance coverage," said Senate Budget Chairman Tom Lee, R-Brandon. "And I understand that. I'm not surprised to see that. And our response indicates that we are not prepared to walk away from that."In response, Crisafulli made what he later described as his "best" offer: $600 million in state funding that could be used to draw down nearly $1 billion in federal funds.Crisafulli did not say where in the state's $80 billion budget the $600 million would come from. Those details had not yet been worked out, he said."The fact of the matter is we're at a point right now where we just have to get past the starting line," he said, suggesting the two chambers begin meeting this weekend to begin building a budget.Senate leaders, however, said they would prefer to extend the legislative session through June 30 and wait for a response from the U.S. Centers for Medicare and Medicaid Services on the proposed LIP successor program. "Rather than putting the cart before the horse, we would much prefer to have a response from CMS," he said.Lee had other issues with the House offer. For example, he said using state money to replace the LIP program would be like charging Floridians twice for the same services, as Floridians already pay federal taxes.His counterpart in the House, Budget Chairman Richard Corcoran, R-Land O'Lakes, called the conversations a positive development. But he didn't hesitate when asked about the Senate's insistence on Medicaid expansion."It's a no-go," Corcoran said.With the two chambers so far apart, there was little common ground to begin basic budget negotiations that ordinarily would take place over the last weekend of the legislative session."There's no need for you to stay in town," Lee told senators when they finished their business around 1:30 p.m. Later, he acknowledged he would be returning home this weekend, as well, underscoring that even top Senate budget officials had no need to stay behind either. The House went into recess at 5 p.m., but returned unexpectedly to consider several additional bills.For a few minutes, the Florida Capitol buzzed with rumors that the House might end the session one week early, a strategy that would have killed hundreds of legislative proposals and forced the Senate to return for a special budget session.During the break, House Rules Chairman Ritch Workman, R-Melbourne, said there was no plan to go home early. But he wasn't willing to count it out yet."That could happen, if they keep acting like they're acting," he said, pointing at the Senate chamber.Contact Kathleen McGrory at [email protected] Follow @kmcgrory. Contact Michael Van Sickler at [email protected] Follow @mikevansickler.