Defence lawyers for Larry O'Brien argued Tuesday that the influence peddling charges against the Ottawa mayor aren't even legal.

The Crown wrapped up its case Tuesday and now the defence is arguing for the judge to make a directed verdict, which is usually requested when the Crown hasn't provided enough evidence to prove its case.

"It's our position that even if the Crown had managed to prove its theory beyond a reasonable doubt, a conviction of Mr. O'Brien on both the counts is legally impossible," said David Paciocco, a lawyer introduced by the mayor's defence team on Tuesday.

Rather than asking the judge to toss out the case for lack of evidence, O'Brien's lawyers say the alleged crime is merely "the stock in trade of political discourse."

Charges against the mayor stem from allegations he encouraged Terry Kilrea to drop out of the 2006 mayor's race in exchange for a federal appointment to the National Parole Board.

Defence lawyers argued the influence peddling charges against the mayor should only be applied if the accused gets some sort of financial gain; not a political gain.

In other words, it's not a crime even if O'Brien was proven to have discussed an appointment with Kilrea.

"There is that grey area between politics and when politics might cross the boundaries into criminal law," said Norm Boxall, a criminal lawyer who is watching the case closely.

"The defence is saying, we don't accept (the evidence) necessarily -- but even if you accepted (it), there's not sufficient evidence to find this man guilty and the charge should be dismissed now."

Paciocco told the judge if the case stands-up in court, it will "effectively be declaring many honourable MPs and prime ministers criminals."

"I'm going to be making the submission you can't argue one thing for Mr. O'Brien and another thing for a member of Parliament who crosses the floor in exchange for a cabinet post," said Paciocco.

"It's going to be the same thing for everybody."

Paciocco said he is also prepared to call an expert witness to support his arguments. However, the witness is apparently at a conference and is unable to appear before the court until Monday.

The Crown told reporters calling a witness after arguing for a directed verdict is highly unusual. The judge is now expected to decide on how to proceed with the trial on Monday.

With files from The Canadian Press