HARRISBURG — Gov. Ed Rendell plans to take his case for expanding state-subsidized health coverage for uninsured adults on the road next month in a statewide bus tour designed to drum up support for the proposal.

But Republican leaders in the Legislature remain adamantly opposed to the idea of a payroll tax on certain businesses that do not insure workers.

A coalition of nurses, small business owners and uninsured people is scheduled to rally in support of Rendell's "Cover All Pennsylvanians" proposal at the Capitol on Tuesday. The bus tour is scheduled to begin Oct. 9 and last about a week.

The tour is intended to call attention to Pennsylvanians who cannot afford health insurance, said Chuck Ardo, spokesman for the Democratic governor. An estimated 800,000 adults are uninsured.

Staunch opposition to a payroll tax that would be levied on all but the smallest businesses that do not cover their employees has stalled the nearly $317 million plan unveiled earlier this year. It is the cornerstone of Rendell's broader "Prescription for Pennsylvania" aimed at reducing the cost and improving the quality of health care.

Business lobbyists and Republican legislative leaders have said increasing state spending is the wrong approach and have questioned whether such a payroll tax would be legal. Some critics say Rendell's proposal resembles a now-overturned Maryland law that would have forced Wal-Mart to spend more on employee health care.

The expansion would also be financed with federal Medicaid dollars and money the state currently spends on its adultBasic program for uninsured adults, as well as premiums that would be paid by small businesses and health plan enrollees.