Horwath, who met with Wynne today, says she laid out her "expectations" about the upcoming budget.
The list of demands include a 15 per cent cut in auto insurance premiums and $30 million in funding for home care.
Wynne has said she's willing to listen to the NDP on auto insurance, but she's more interested in tackling fraud in the system.
The governing Liberals need the support of at least one of the opposition parties to pass the budget and avoid an election.
Horwath wouldn't say whether the NDP would vote against the budget if it doesn't meet all of their demands.