Ottawa Mayor Larry O'Brien Friday has denied allegations that his ex-wife approached a contractor who works for the city and asked for a donation to the mayor's legal-defence fund.

The mayor is facing two criminal charges for allegedly offering to use his influence to arrange a federal position for a rival candidate in the 2006 mayoral election if the rival would drop out of the race. The trial is to begin next year.

The Ottawa Citizen newspaper reported Friday that Ottawa police had received a letter from a municipal contractor raising a concern about being approached by the mayor's ex-wife, Debbie O'Brien.

Chief Vern White of the Ottawa police forwarded the letter to the Ontario Provincial Police, the newspaper said.

O'Brien startled journalists at dinner-time Thursday by calling a hasty news conference at city hall to deny in advance what he had heard the newspaper would report on Friday.

"When I heard the rumour, I decided to get out in front of it and say, 'Hey, look, I talked to Debbie, asked her if it was true, and she said No,' " O'Brien told CBC News Friday morning.

"She's an honourable person, a person of great strength and great character, and I decided to … send two messages: one, this is not true, patently untrue; and second, to that person [presumably, the reporter who wrote the story], stay away from my family. You make it too personal."

While running for mayor in 2006, O'Brien is alleged to have offered to help his opponent, Terry Kilrea, get a job on the National Parole Board if Kilrea pulled out of the election race.

After an eight-month OPP investigation, O'Brien was charged with pretending to have influence with the government of Canada or with a minister of the government, contrary to Sec. 121 of the Criminal Code.

O'Brien was also charged with negotiating an appointment, influencing or negotiating appointments or dealing in offices, contrary to Sec. 125 of the Criminal Code.

The allegations have not been proved in court.

His trial is set to begin April 6, 2009.