An expert on election law has waded into the debate over Mayor Rob Ford’s campaign finances, arguing it appears Ford broke the rules on three fronts.

Peter Rosenthal, a lawyer and University of Toronto math professor, has filed an opinion on behalf of Ted Ho, one of several citizens asking the city for a “compliance audit” of Ford’s campaign finances.

Rosenthal, who has represented the Green Party of Canada and Ottawa-based non-profit Democracy Watch on election issues, says in his brief that:

• Ford’s campaign filings appear to wrongly list some functions, including his March 26, 2010, campaign launch, as fundraisers, and therefore exempt from the $1,305,066.65 spending cap. Revenue collected at the door was $7,655, plus $250 in “pass the hat cash,” while total expenses were $34,371.72. Adding even one of the questionable events to campaign spending would push Ford past the legal limit, Rosenthal says.

• Invoices to the campaign from family company Doug Ford Holdings Inc. raise the possibility the campaign borrowed improperly from a company that is not a bank or recognized lending institution. If any of the invoices weren’t repaid, the campaign accepted a corporate donation, which is illegal under Toronto’s election bylaw, he argues.

• A news report about Ford supporters with campaign shirts and signs on a bus shortly before he signed his nomination papers suggests the campaign improperly incurred expenses before he was a candidate.

Ford’s lawyer, Tom Barlow, will on Friday ask the city’s compliance audit committee to reject Ho’s request for an audit, along with two other requests sparked by a Globe and Mail story outlining the unorthodox campaign financing.

“Everything that was done was done in accordance with the requirements of the Municipal Elections Act,” Barlow told reporters last Friday, after the committee agreed to wait a week and hear all three requests together.

Barlow was expected to file his written submission Wednesday. However, city officials said Wednesday afternoon it had yet to appear, and was expected Thursday.

Barlow did not return the Star’s call and email asking for comment.