A group against the redevelopment of Lansdowne Park has filed a lawsuit against the City of Ottawa that threatens the future of the multi-million dollar project.

Two citizens, Gary Sealey and Doug Ward, along with the Friends of Lansdowne claim the city did not follow its own competitive bidding process when it entered into a $175-million deal with three Ottawa developers.

However, the city says the deal was approved by third-party lawyers.

The lawsuit, filed in Ontario Supreme Court, has the potential to kill the redevelopment plans. The case won't be heard until November.