The Supreme Court of Canada will look at the legality of Ontario's decision to slash the size of Toronto's city council.

Two years ago, Ontario Premier Doug Ford passed legislation midway through a municipal election campaign, cutting the number of Toronto council seats to 25 from 47.

At the time, Ford — a former Toronto city councillor and failed mayoral candidate — said the move would improve decision-making and save $25 million.

Critics accused him of political interference and flouting democracy.

A provincial judge found the law unconstitutional, saying it infringed on the free-expression rights of candidates by affecting their ability to campaign, and those of voters by denying them the right to cast a ballot that could result in effective representation.

However, the Ontario Court of Appeal overturned the decision last year, prompting the city to seek a hearing in the Supreme Court.