It could be days or weeks before the judge residing over the criminal trial of Ottawa Mayor Larry O'Brien will decide whether or not he'll throw out the case against the mayor - a decision which observers say could have huge repercussions on the political landscape.

The mayor's legal team asked Justice Douglas Cunningham to make a directed verdict on the case last week, which is usually requested when the defence feels the Crown hasn't provided enough evidence to prove its case.

Although O'Brien's lawyers argued Monday that the Crown failed to prove its case beyond a reasonable doubt, the mayor's legal team maintains charges against the mayor aren't even legal.

The charges against O'Brien stem from allegations he encouraged fellow mayoral candidate Terry Kilrea to drop out of the 2006 municipal race in exchange for a federal appointment to the National Parole Board.

Defence lawyers argued that the influence peddling charges should only be applied if the accused gained financially, not politically.

While observers say it's not a surprise the defence requested a directed verdict in the case, University of Ottawa law professor Blair Crew said it is unusual for the defence to challenge the legality of the charges.

"I don't think that it's the best strategy. I think the evidence overall is insufficient and I would be surprised to find that the defence was not relying on the overall insufficiency of the evidence to a greater degree," Crew told CTV Ottawa on Monday.

Crew said although the law is broadly worded, he doubts the defence will succeed in their claims that charges against the mayor aren't legal.

"The statute is worded broadly enough, in terms of there being any kind of reward offered, such that I think the judge can conclude that a withdraw from the race and an offer for an appointment to the parole board would be sufficient for the legislation . . . on that ground, I don't think the defence can succeed," Crew said.

However, defence lawyer David Paciocco said the case shows how politicians do business. If it stands up in court, he said it would "effectively be declaring many honourable MPs and prime ministers criminals."

He drew similarities to situations in which federal politicians, such as Belinda Stronach and Scott Brison, received cabinet posts after crossing the floor.

If the judge does side with the defence, Crew said the ruling could have a huge impact on the political landscape.

"If Justice Cunningham accepted that it had to be a monetary reward, then that effectively rewrites the criminal code and sanctions what happens on Parliament Hill all the time," he said.

However, if the judge rules that an appointment offer is a sufficient reward, Crew said "people on Parliament Hill are going to have to be an awful lot more careful in the future."

Paciocco said he was prepared to call an expert witness to support his arguments. However, the judge ruled Monday that calling a witness to explain the law was unnecessary.

The Crown will argue the directed verdict on Tuesday. It's not yet known how long it will take the judge to make a decision on the matter.

However, Crew said he wouldn't be surprised if the judge rules that the Crown failed to prove its case, rather than wading into the debate on the legitimacy of the charges.

"It's a safer route for the judge to go," he said.

With a report from CTV Ottawa's Catherine Lathem