In a move that likely will draw a constitutional challenge, Gov. Rick Scott on Monday signed a controversial bill that would allow random drug testing of state employees.

Scott, who prompted a federal court fight last year when he issued an executive order to begin drug testing, quietly notified the secretary of state at 5:10 p.m. that he had signed the bill.

The Republican-dominated Legislature overwhelmingly approved the measure, HB 1205, this month, with supporters saying the private sector already uses such programs to improve safety and worker productivity.

"I've had a drug-free workplace for more than 20 years,'' Sen. Jack Latvala, R-Clearwater, said before a vote on the final day of the legislative session. "I believe that it has contributed to higher quality employees."

But legislative opponents and groups such as the American Civil Liberties Union of Florida argued repeatedly during the recently completed legislative session that the idea would violate state employees' constitutional rights.

"We're talking less personal freedom without probable cause,'' Sen. Chris Smith, D-Fort Lauderdale, said during the debate. "This is more government intrusion and more costs."

The bill would allow, but not require, agencies to conduct random testing every three months. Agencies would use a computer system to choose employees to be tested, with the total not exceeding 10 percent of the agency work force.

Also, agencies would have to pay for the tests out of their overall budgets, which would help prevent additional costs to the state. The law takes effect July 1.

Scott issued an executive order last year to start employee drug testing, but the order is largely on hold because of a court challenge. The Department of Corrections has continued with drug testing during the challenge.

Supporters dismissed arguments that HB 1205 would violate workers' constitutional rights. But the legal fight likely will center on whether government agencies have the right to conduct "suspicionless" drug tests of workers.

A House staff analysis said that some of the issues that "may be arguable are whether the suspicionless drug testing of public employees or job applicants contravenes reasonable expectations of privacy and whether the government has a special need for such drug testing that outweighs the privacy interests of such employees and applicants."