The campaign of Rep. Lincoln Diaz-Balart (R-Fla.) today issued a scathing attack on a poll on his re-election contest that was published in today’s edition of Roll Call.

In the release, the campaign called the poll “profoundly flawed” because it had too many Democrats in the sample size.

The campaign made available to Roll Call a survey that its own pollster had conducted in June showing the Congressman with a 12-point lead over his Democratic challenger — a contrast to the Roll Call poll that showed Diaz-Balart trailing by 2 points.

In the Roll Call poll, conducted Aug. 24-26 by the automated firm SurveyUSA, former Hialeah Mayor Raul Martinez got 48 percent of the vote and Diaz-Balart got 46 percent. The survey of 632 likely voters had a 4-point margin of error.

In Diaz-Balart’s own survey of 405 likely voters, taken June 19-22, the Congressman led Martinez 48 percent to 36 percent. That poll, conducted by telephone, by a GOP polling firm, Hill Research Associates, had a 4.9-point error margin.

Regardless of which poll is more accurate, Diaz-Balart is undoubtedly facing his toughest race since he was elected to Congress in 1992. The Congressman has run unopposed five times, and his “weakest” showing was in 2006, when he took 59 percent of the vote.