AUGUSTA, Maine — Supporters of a proposed tax on Maine high earners to pay for home care for elderly and disabled people enough signatures from voters to get the initiative on the November ballot if lawmakers don’t pass it first, Democratic Secretary of State Matt Dunlap said Friday.

The chance of lawmakers passing the proposal is unclear, however, with House Republicans and business groups already expressing strong opposition.

The proposal would increase taxes on high-earning Mainers to raise $310 million annually for so-called “universal home care” for the elderly and disabled.

If successful, Maine — the nation’s oldest state — could be among the first to pass universal home care.

Hawaii recently passed a law providing up to $70 a day worth of services for a caregiver who assists a loved one who’s over age 60 and has a full-time job. The state of Washington is considering a law to increase payroll contributions to provide family caregivers with $100 a day for a year.

Maine People’s Alliance spokesman Mike Tipping has said there’s an appetite in Maine to make the wealthy contribute more as income equality grows nationwide. The campaign has reported receiving a $350,000 boost from nonprofits linked to billionaire philanthropist George Soros.

Under the proposal, employers and employees would together face a new 3.8 percent tax on the portion of wages and income above the amount that’s subject to Social Security employment taxes. In-home care providers and other groups that receive funds from the universal home care program would have to spend at least 77 percent on “direct service worker costs,” according to the proposal.

Conservatives and business groups argue that the tax would be worse for small businesses than the voter-approved, 3 percent surtax for school funding that lawmakers ended up repealing last year.

“Here we go again with another proposal to slam small business owners and self-employed people with even higher state taxes, making Maine one of the highest taxed states in the nation,” said National Federation of Independent Business Maine State Director David Clough.