BEIJING, July 13 (Xinhuanet) -- Florida state Rep. Bob Allen, co-chairman of Sen. John McCain's Florida campaign, was arrested Wednesday in a public park for allegedly offering an undercover police officer 20 U.S. dollars for a sex act, Titusville police said.

    Allen faces charges of solicitation for prostitution. His attorney, Philip Lupo of Titusville, said the charge was a second-degree misdemeanor.

    Allen told CNN affiliate WFTV the incident was "a very big misunderstanding. This is a very gross mistake, a very big mistake.

    Allen said he helped build the park, and was there looking around. At a late-afternoon press conference Thursday, Allen made a statement but took no questions.

    "I am filing a not guilty plea. I am vigorously going to fight this," he said. "I am not resigning my office, because the people elected me [and] want me to do a good job and I am going to do a good job for them in finishing this term. ...

    "This is an ugly and unpleasant situation that has been thrust upon me and my family that is not true, it is inaccurate and it is therefore not guilty."

    There was no initial comment from the McCain campaign.

    (Agencies)