A Portland activist who helped fight the sale of a public park to a private developer in 2014 is expected to formally declare her candidacy for the City Council on Sunday.

Bree LaCasse announced her candidacy in a statement Saturday, ahead of an event scheduled for noon Sunday in Congress Square Park.

Her opponent is longtime Councilor Jill Duson.

LaCasse helped organize opposition to the sale of Congress Square Park to a hotel, whose owners wanted to use the space to expand an events and dining area, but citizens rejected the idea in a referendum.

LaCasse is currently executive director of Friends of Congress Square Park, the group that now advocates for better, higher usages of the public space, which is expected to be redesigned and refurbished.

The election is in November. Nomination papers are due to City Hall by July 3.