LANSING (AP) — Michigan Gov. Gretchen Whitmer on Thursday threatened to veto legislation that would cut what are the country’s highest average auto insurance premiums, saying it falls short and urging the Republican-led Legislature not to send it to her desk without negotiated changes.

The Democratic governor said a state House-passed plan would not guarantee savings for motorists or go far enough in ending the use of non-driving factors to set rates. The GOP-controlled state Senate also approved a bill this week following years of legislative stalemates over the issue.

“They can either negotiate in good faith and send me a good bill that actually protects consumers while we also continue to negotiate the budget that fixes the damn roads, or they can send one of the current bills that fails to protect Michigan drivers and we can start all over again,” said Whitmer, who has proposed an unpopular 45-cents-a-gallon fuel tax increase to boost funding for deteriorating roads.

The House legislation — approved at around 2 a.m. Thursday during a marathon session — would allow motorists with health insurance to forego mandatory unlimited personal injury protection, or PIP, which only Michigan currently requires. Insurers would have to cut PIP rates, which can make up about half of a customer’s bill, by between 10% and 100% for five years, depending on the coverage chosen between $0 and $500,000. That could amount to an estimated $120 and $1,200 in savings for someone paying $2,400 annually per car, assuming the PIP fee accounts for half their bill, according to Republican projections.