The Crown attorney at the criminal trial of Ottawa Mayor Larry O'Brien insists the influence peddling charges against the mayor are legal.

The Crown argued against the defence's request to throw out the case on Tuesday.

Although the mayor's legal team argued the Crown failed to prove its case in court, defence lawyers also contended that 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.

However, defence lawyers have argued the influence peddling charges should only be applied if the accused gained financially, not politically.

Crown attorney Scott Hutchison told the court on Tuesday that when it comes to influence peddling charges, "a promise to do something is sufficient."

"O'Brien was prepared to trade, to exchange his services as an influencer, for a benefit of Mr. Kilrea leaving the race," Hutchison said.

Justice Douglas Cunningham, who is hearing the case without a jury, challenged some of Hutchison's arguments on Tuesday.

"Perhaps one of the absurdities might be to extend the meaning (of the law) to capture trading in political favours -- something that happens all the time," he said.

"It seems to me the very nature of political activity does involve a certain amount of trading in promises -- `if you do something for me, if you support the party, you will be rewarded.' That's the nature of patronage."

Hutchison defended his position by stating there is nothing "absurd" about the issue.

"It's not an absurd result to say you can't buy something that you value by trading on a government position or a government contract. There's nothing absurd about that," he said.

The trial will resume on June 26, when the judge will announce whether the case will be thrown out.

In the meantime, O'Brien has the option of returning to the mayor's chair. The mayor offered no comment to reporters when they asked him about his intentions on Tuesday afternoon.

If the judge does side with the defence, legal observers say the ruling could have a huge impact on the political landscape.

With files from The Canadian Press