A controversial proposal that require thousands of businesses in Tennessee to do pre-employment, post-accident and reasonable suspicion drug tests passed another hurdle Thursday morning.

After little discussion, the House Calendar and Rules Committee passed the bill on a unanimous voice vote, sending the bill to the House floor on May 3.

The bill's House sponsor, Rob Briley of Nashville, said after the vote that he was confident that he could get the bill passed on the House floor. However, there are major differences between the House and Senate versions of the bill, which raises the possibility that it could end up in a conference committee in mid-May.

The Senate version of the bill requires all companies with five or more employees that do business with the state, plus all local governments in Tennessee, to have a "drug-free workplace" program that complies with Title 50, Chapter 9 of Tennessee Code. It passed the full Senate with only one dissenting vote last week.

The House version of the bill applies only to companies that do business with the state.

One of the things that has made this bill so intriguing is that it is being heavily lobbied by Jim Neeley of the Tennessee AFL-CIO Labor Council. Last week, Mr. Neeley told NashvillePost.com that "there is no good reason in the world for anyone to be against this bill."

Most lobbyists hardly noticed the bill until it passed the Senate last week. Now, most business lobbyists are watching it closely, including the Tennessee Association of Business, the National Federation of Independent Businesses, the Tennessee Roadbuilders Association and the Association of General Contractors.

On Thursday, Bob Pitts of the AGC told NashvillePost.com that "we encourage drug testing by our members." But he said his group was vehemently against the bill because they thought it was unjustified and would have enormous hidden costs.

"I haven't seen any justification that it is necessary," Mr. Pitts. "And I don't know if anyone understands or has studied the long-term impact of this law in terms of cost. For example, this many drive some away from government work, which will increase the cost of the government building projects."

Mr. Pitts also said he has been unable to find any other state in the country that has passed such a law.