Washington ? The Federal Trade Commission will announce Friday its plan for investigating and regulating possible market manipulation by oil companies, traders and others, a Democratic senator said Thursday.

Under legislation passed late last year, violators could face fines of $1 million a day.

Sen. Maria Cantwell, D-Wash., said the best way to bring down the price of gasoline at the pump is for the administration to start seriously policing the oil industry.

“The jury is still out on how tough the FTC will be,” Cantwell said in an interview. “We see smoke. We need the FTC to determine whether there is a fire.”

The legislation that Congress approved in December granted the FTC powers to investigate petroleum markets. Cantwell sponsored the legislation and has been the Democratic leader on many energy issues over the past several years.