MADISON, Wis. -- A conservative think tank said that a plan to provide universal health care coverage in Wisconsin would raise taxes on businesses and cut many residents' benefits.

The Wisconsin Policy Research Institute also said that revenues needed to run the plan would not increase as quickly as health care costs. The group warned the gap in revenue would lead to additional tax increases or benefit cuts.

State Rep. Jon Richards, D-Milwaukee, is a top supporter of the Wisconsin Health Plan, and he said that the study is unreliable and the plan is still being revised.

Richards' plan would cover all Wisconsin residents under age 65. Backers originally proposed paying for the program with a new payroll tax on business but Richards said that other funding options are being studied.

Supporters said that the plan would rein in rising costs, provide coverage to the uninsured and replace the patchwork of state health care programs for the poor.

The institute's study said that a large tax increase would be needed to fully fund the plan and warns that many employees would see a cut in benefits under the new system.