LANSING – As talks continue between Republican legislative leaders and Democratic Gov. Gretchen Whitmer on a plan to reduce Michigan's highest-in-the nation auto insurance premiums, House Democrats said Thursday they have their own plan to cut premiums by 40%.

House Minority Leader Christine Greig, D-Farmington Hills, said the GOP bills call for reductions in portions of the auto insurance bill, but her party's plan would mandate an across-the-board cut of at least 40% in the total premiums paid by all Michigan drivers.

"I don't want to cross my fingers and hope," Greig told reporters at a Capitol news conference. "I want a guarantee."

Greig said the plan would keep unlimited catastrophic medical coverage for all drivers, but allow seniors to use "Medicaid and other lifetime retirement health care" as an alternative to personal injury protection (PIP) coverage that is now mandated for all.

Tricia Kinley, executive director of the Insurance Alliance of Michigan, blasted the plan as "false advertising" because she said it fails to address high hospital charges and other factors driving up Michigan auto insurance costs.

Other features of the House Democratic plan, which has not yet been introduced in bill form, would:

Ban the use of discriminatory and non-driving factors such as ZIP codes, marital status, credit scores, and educational attainment in setting premiums.

Guarantee drivers a discount when they can coordinate their auto insurance coverage with their health care.

Reduce insurance fraud by creating a consumer protection fraud authority.

Reduce lawsuits by extending the amount of time parties have to file a claim from one to three years.

Increase transparency at the Michigan Catastrophic Claims Authority, which assesses an annual per-driver fee — currently $192 per vehicle — to pay medical claims in excess of $550,000.

Unlike the Republican plans, the Democratic plan does not include a fee schedule designed to reduce the cost of medical procedures following auto accidents.

That's a major weakness, House Speaker Lee Chatfield, R-Levering, said Thursday.

"Without a fee schedule, you can't simply put a wizard hat on and wave your wand across the state of Michigan and sprinkle fairy dust and expect that car insurance rates are going to drop," Chatfield said.

Also, "they're attempting to guarantee rate reductions without offering real choice," he said.

Democratic lawmakers did not answer directly when asked how much of the 40% premium reduction they expected to come from insurance company profits.

More:What Michigan no-fault reform bills would mean for drivers

More:Whitmer blasts GOP auto insurance reforms, says she's 'done playing games'

Rep. Donna Lasinski, D-Scio Township, said savings would come from a number of areas, including fewer lawsuits, reduced fraud and ending discriminatory price-setting.

Rep. Sherry Gay-Dagnogo, D-Detroit, said most insurance companies don't make their money from auto insurance. They make money investing clients' premiums, she said. "The reductions ... are not going to cut into their investment strategy," she said.

Asked whether insurance companies could afford a 40% rollback, Greig said: "Look at the cash reserves of a lot of these insurance companies."

Without changes, Whitmer has promised to veto the current auto insurance bills.

Final passage of a unified GOP auto bill in the House and Senate was expected to happen as soon as Thursday.

But Chatfield and Senate Majority Leader Mike Shirkey, R-Clarklake, told reporters Thursday they plan to wait and allow for more negotiations with the governor's office.

"Fine wine takes time and this is a very fine wine for the people of Michigan," said Shirkey.

Chatfield said recent talks have been productive and the administration has presented ideas to Republicans “that actually move in a direction that we can have some optimism that we could get to a bill signing in the not-too-distant future.”

Whitmer said Thursday she is open to allowing motorists to forgo unlimited coverage and choose a lesser amount, but “the zero coverage option is where I have to draw the line.” She told the Associated Press that such a move could “bankrupt people,” shift cost to taxpayers and undermine hospitals’ trauma centers.

Michigan is the only state to require mandatory personal injury protection, or PIP.

Kinley said she's pleased to see more lawmakers open to changes to address Michigan's auto insurance costs.

"Unfortunately, the House Democrats plan will not do that," Kinley said.

"It’s false advertising to promise savings without including real reforms to crack down on fraud and abuse by trial attorneys who profit off the status quo, rein in overcharging by big hospitals and give consumers a choice in their level of medical coverage.”

Early on May 9, the state House approved massive changes to Michigan's auto insurance law that were introduced only late Wednesday. House Bill 4397 would replace Michigan's unlimited medical coverage for catastrophic injuries with a range of personal injury protection coverage options and mandate five years of reduced rates for that portion of a motorist's auto insurance bill. Three Democrats — two from Detroit — joined all Republicans to pass the measure 61-49.

The House action followed similar action on May 7 in the GOP-controlled Senate, where major auto insurance changes were introduced, rushed through committee and approved in a 24-14 vote, with two Detroit Democrats voting yes with the Republicans. Senate Bill 1 would not mandate specific reductions in portions of the auto insurance premium, as the House bill would. But it, too, would give a range of coverage options and would phase out the Michigan Catastrophic Claims Association. That piece of the package alone was expected to reduce the current catastrophic claims surcharge of $192 per vehicle to about $40.

Whitmer said she would veto either measure because neither guarantees significant rate reductions, provides adequate consumer protections, or prevents discrimination in rate-setting based on non-driving factors.

Both the House and Senate versions include limits on the use of non-driving factors, such as ZIP codes, in setting auto insurance premiums. However, many Democrats and other critics say those safeguards do not go far enough.

Contact Paul Egan: 517-372-8660 or pegan@freepress.com. Follow him on Twitter @paulegan4. Read more on Michigan politics and sign up for our elections newsletter. Staff writer Kathleen Gray and the Associated Press contributed to this report.