Sen. George LeMieux (R-Fla.) on Tuesday publicly confirmed that he would support the GOP nominee in the race for Florida’s open Senate seat and oppose his friend and former boss, Gov. Charlie Crist, who last week chose to leave the Republican Party and run for Senate as an Independent.

LeMieux, who was appointed to the Senate by Crist last summer after Sen. Mel Martinez (R-Fla.) resigned his seat, said he talked with Crist by telephone just hours before the governor made his announcement to run as an Independent and urged him to remain a Republican. Crist exited the GOP Senate primary after several public opinion polls taken over a period of months showed him far behind his main competition for the nomination, former state Speaker Marco Rubio.

LeMieux, in a brief interview with reporters just off the Senate floor, declined to speculate as to what help he might provide Rubio in the general election, saying: “I haven’t crossed that bridge yet.” But he repeated his pledge to support the GOP nominee in the Senate race. LeMieux formerly served as Crist’s chief of staff.

“I’m saddened that he made the decision. Up until the last day — the day of his announcement — I called him and talked to him on the phone and urged him to stay in the Republican Party. I regret that he made the decision to leave the Republican Party. I have enormous respect for the governor; he’s a friend of mine,” LeMieux said. “I’m not going to say anything ill about him. I just wish he would have stuck with the Republican Party, and I believe in the principles of the party. And, although he is my friend, I can’t join him in his decision to leave the party.”

LeMieux said he spoke with Crist twice in the three weeks leading up to Crist’s announcement. LeMieux said that, in this case, his commitment to the philosophical principles of the Republican Party trumped his loyalty to a man he referred to as “a very good friend of mine — someone who I spent more time with in five years than I probably spent with my own family.”

“It was not a choice that I wanted to make. It was sort of a choice that was thrust upon me,” LeMieux said.

LeMieux said it’s hard to predict how a three-person race for Senate will play out, although he hinted that he doesn’t give Crist much of a chance.

The Florida primary election is scheduled for Aug. 24, at which point Crist, Rubio and the winner of the Democratic primary are likely to emerge as the three main candidates in the race. Rep. Kendrick Meek (Fla.) and billionaire real estate mogul Jeff Greene are running in the Democratic primary.

“We’ve never had anything like this in Florida before. I believe in the end that the system is weighted toward the parties. So, it’s very difficult to run without a party,” said LeMieux, who previously worked for Crist going back to the governor’s days as Florida attorney general.