Brian Mast has a big lead in Florida’s 18th Congressional District.

Mast leads the field with 39 percent support, according to internal polling data obtained by FloridaPolitics.com. The Logit Group poll found Rebecca Negron was in second, with 19 percent, followed by Mark Freeman with 18 percent. The survey found 10 percent of voters said they were backing Carl Domino.

The automated phone survey was conducted Aug. 4 through Aug. 7. The poll surveyed 364 likely Republican primary voters.

“This poll is absolutely suspect with no cross tabs and no analysis, and is no where near what our polling shows,” said Sarah Bascom, a spokeswoman for Negron.  “This is a last ditch effort to sway voters toward a candidate that is failing to connect with the voters and has resorted to negative campaigning.  The only poll that matters is on Election Day, and that one cannot be padded for Mast no matter how much he would like to.

Mast proved to be the most-liked candidate, with 54 percent of respondents saying they had a favorable opinion of him. Nine percent said they had an unfavorable view of Mast, while 36 percent said they were unsure.

The survey found 41 percent of respondents said they had a favorable opinion of Negron, the wife of Senate President Designate Joe Negron. One in four respondents said they had an unfavorable opinion, while 34 percent said they were unsure.

Forty percent of respondents said they had a favorable view of Freeman; while 24 percent said they had a favorable view of Domino.

The four Republicans are vying to replace Rep. Patrick Murphy in the U.S. House. Murphy decided to run for U.S. Senate, instead of re-election. Three Democrats — Jonathan Chane, Randy Perkins, and John Xuna — are also running.

The primary is Aug. 30.