MADISON, Wisconsin -- Former Wisconsin Gov. Tommy Thompson was one of the first high-profile supporters of tiny microchips implanted in people's arms that would allow doctors to access medical information.

Now the state he once lead is poised to become the first in the United States to ban governments and private businesses from forcing such implants on employees, privacy advocates say.

A proposal moving through the state Legislature would prohibit anyone from requiring people to have the tiny chips embedded in them or doing so without their knowledge. Violators would face fines of up to $10,000.

The plan won approval in the Assembly last month. The state Senate on Tuesday is scheduled to consider the measure, which would allow for the implants if the person gives consent.

Current Gov. Jim Doyle would sign the bill, a spokesman said.

Supporters want the law in place before companies and governments could use them to keep track of their employees.

VeriChip Corp. of Delray Beach, Florida, is the only company with U.S. federal approval to implant such chips in people. The company so far has implanted 2,500 people worldwide with chips the size of a grain of rice under the skin of their upper arms, said spokesman John O. Procter.

In February, a Cincinnati surveillance equipment company became the first U.S. business to use this application when a handful of employees voluntarily got implants to allow them to enter secure rooms. Some employees in the Mexico attorney general's office have also been implanted with chips, whose signals are recognized by readers in doorways.

Procter said VeriChip supports the spirit of the bill and would not work with companies forcing employees to get implants. However, he said the implants are superior to employee badges or key chains as a way to limit access.

Privacy advocates say they are unaware of any companies forcing implants but are worried the technology is taking off with little debate about potential abuses.