The City of Ottawa can expect one more legal challenge to the redevelopment of Lansdowne Park.

City solicitor Rick O'Connor sent a note to councillors and media Tuesday night saying his office is expecting a Supreme Court challenge from John Martin — the main backer of the Lansdowne Park Conservancy.

The city last week gave the final green light to the multi-million dollar project.

O'Connor had said earlier this summer that while it was possible the Lansdowne Park Conservancy could appeal their case to the Supreme Court, "it would be extremely difficult" to get the court to hear the case.

The Lansdowne Park Conservancy was the second group to launch a legal challenge of the city's partnership with Ottawa Sports and Entertainment Group.

The first group, Friends of Lansdowne, had earlier questioned the legality of the city's decision to enter into a sole-source agreement with OSEG but lost its legal challenge and again lost its appeal. Friends of Lansdowne said they would not appeal to the Supreme Court.

In March a lower court rejected Lansdowne Park Conservancy's legal challenge, saying it constituted an abuse of process and awarding the city $10,000 in legal costs. The Court of Appeal also dismissed the case, and awarded the city $1,000 in legal costs.