NASHVILLE (AP) - While Gov. Bill Haslam is keeping the door open to an expansion of the public pre-kindergarten program in Tennessee, any such move would remain a tough sell among some fellow Republicans in the Legislature.

Haslam stressed that a federal notice that Tennessee intends to apply for a share of federal money available for pre-K expansion doesn't mean the state will necessarily follow through. The governor said this week he is still awaiting the results of a multi-year Vanderbilt study on the effectiveness of the program before making up his mind.

"We're still waiting on the study from Vanderbilt University, but we thought it was worth it to put the application in," Haslam said earlier this week.

Tennessee could qualify for up to $17.5 million per year under the competitive grant federal grant program that is required to decide on disbursing the money to the states by the end of the year.

Should Haslam ultimately dec ide to pursue more money for pre-K, he will have to persuade Republican Senate Speaker Ron Ramsey, a long-time critic of the program for 4-year olds. Ramsey called it "a liberal, feel-good program that's not working."

Ramsey acknowledged that the federal program would not involve state money, but questioned any expansion beyond children from low-income households.

"Any dime that we spend on that is a dime that comes away from K-12," he said.

Tennessee spends about $86.5 million per year on the program, funding 935 pre-K classrooms around the state with an enrollment of more than 18,000 children.

Early results from the Vanderbilt study tracking pre-K students' performance over time found greater academic gains than their peers who didn't attend.

But critics have that the 2011 report also revealed that many of those advantages were erased by the time students reached grades three through five.

The authors of the early report acknowledged that one shortcoming of their data was that they did not know whether students in the "non-pre-K" group might have actually attended private pre-kindergarten programs.

The Tennessean reported this week that the next set of the Vanderbilt results from the study won't be ready for a year from now. So it's unclear how the study began in 2009 could influence a final decision on applying for the federal money by the Oct. 14 deadline.

The pre-K program was begun in 1998 as a $10 million pilot project for about 150 classrooms under then-Gov. Don Sundquist, a Republican. Under his Democratic successor, Phil Bredesen, the program was expanded by nearly 800 classrooms.

Bredesen had called for making pre-K available to any family that chooses to enroll their child, but those plans were put on hold because of the Great Recession, and Haslam hasn't made significant changes in his first term despite its widespread popularity.