LONDON, ONT. -- There's a twist in the trial of London’s so-called "street preachers."

Two men are facing a number of charges under the city’s recently amended public nuisance bylaw.

Steven Ravbar and Matthew Carapella are seeking to launch a constitutional challenge on Tuesday, saying the bylaw violates their freedom of speech.

Ravbar and Carapella are representing themselves during these proceedings and Justice Ralph Cotter spent much of the morning walking them through procedural issues that they need to be aware of during the process.

The two men are facing a total of 18 charges each. All of the charges were read out in court as the hearing got underway.

Most of the charges were filed under a recently added section of the public nuisance bylaw.

The amendment, introduced just over a year ago, states “No person shall, in a public place, unnecessarily interfere with another person's use and enjoyment of the public place by using abusive or insulting language as a personal invective.”

The charter challenges relates to Section 2 of the Canadian Charter of Rights and Freedoms which deals with fundamental freedoms.

Justice Cotter recommended a blended trial, with the constitutional arguments held as a voir dire.

A verdict on charges related to the bylaw won’t be reached until the constitutionality of those charges has been determined. Cotter says evidence presented will inform both decisions.

Ravbar expressed concerns about the blended trial, questioning whether the testimony that will be given in respect to their alleged offences will bias the finding on the constitutional challenge.

The two accused ultimately agreed to the process with Ravbar telling Cotter, “We’ll trust your wisdom and experience sir.”

Prosecutor Jack Huber is planning to call approximately 12 witnesses and many will be women who say they were assailed by the defendants in public places in London.

Cotter assured the men he can make a clear distinction between the constitution matter and the case related to the charges.

Ravbar and Carapella say they have no intention of calling witnesses or submitting further evidence, beyond their initial affidavit.

Cotter says this approach is in the interest of fairness, telling Ravbar and Carapella, “Everyone in the community, including yourselves, needs to have an answer.”

The two men pleaded not guilty to all 18 charges during the Tuesday proceeding, but declined to swear on the bible opting to be affirmed instead, saying swearing on a bible wasn’t appropriate.

Three days will be set aside for the trial, with a hearing to be held on Dec. 16 to determine the exact trial dates.