Lawyer Clayton Ruby is taking his client’s legal fight with Toronto Mayor Rob Ford all the way to the Supreme Court of Canada, where he is seeking a last-ditch appeal of an Ontario court decision that cleared Ford of conflict of interest allegations.

In documents filed to the Supreme Court, Ruby said the Ontario appeals court erred when it overturned an earlier ruling by Justice Charles Hackland of the Ontario Superior Court.

Hackland had ruled in November that Ford broke the Municipal Conflict of Interest Act when he spoke about, then voted on an item at council related to his use of city resources to raise funds for his football charity.

As a councillor, Ford had used city resources to solicit donations to his foundation which provides football equipment to schools that can't afford to buy it. After an investigation by the city's integrity commissioner found Ford's actions were out of line, council voted in August 2010 that Ford should repay the $3,150 in donations out of his own pocket.

Then in February of last year, after Ford had become mayor, he voted on a decision that freed him from having to pay back the donations.

It was the decision to speak to and vote on a matter which concerned his personal finances that Hackland ruled had constituted a conflict of interest.

In January, the Ontario Divisional Court's three-judge panel overturned Hackland's ruling, saying council was acting beyond its authority -- or ultra vires, in legal terminology -- when it asked Ford to repay the funds that had been donated by others. As a result of that decision, all rulings that flowed from the order were also considered nullified.

In his application to the Supreme Court, Ruby said the appeals court misapplied the meaning of ultra vires, and council's mistake shouldn't clear Ford of his conflict of interest breach.

"These errors not only prevented justice from being done in this case, but if upheld, they will contribute to a legal climate in which no decision made by a municipality is secure from collateral attack on the basis that it is purportedly ultra vires," Ruby wrote.

He added: "In sum, the divisional court's decision raises novel and undecided issues at the intersection of constitutional and municipal law. These issues warrant this court's careful consideration."

Ruby filed his application Friday. Once filed, Ford's lawyers will be required to respond. It could take months for the Supreme Court to decide whether it will hear the case.