The preliminary special election to replace former City Councillor Chuck Turner will be held on Feb. 15, with a final election set for March 15, under an order the City Council is expected to approve tomorrow.

Turner, District 7's representative on the 13-member body, was expelled from the council by an 11-1 vote on Dec. 1 after a federal jury found him guilty of corruption charges. District 7 includes Dorchester, Roxbury, Lower Roxbury, and parts of the Fenway, and the South End.

Tito Jackson, a top political aide to Gov. Deval Patrick who has not yet announced his candidacy, is considered the heavy favorite in the race to succeed Turner. Other potential candidates include Monica Dean, a former chief of staff and family member of former state Sen. Dianne Wilkerson; Natalie Carithers, former chief of staff to retiring state Rep. Willie Mae Allen (D-Mattapan); Candace Sealey, district representative for U.S. Rep. Michael Capuano; Roxbury Neighborhood Council's Robert Terrell, and Roxbury attorney Hassan Williams, who unsuccessfully mounted a primary challenge against state Sen. Sonia Chang-Diaz, among others.

Perennial candidate for public office Althea Garrison announced her candidacy via a fax to the Dorchester Reporter last week.

Whoever wins -- as well as those who lose and are interested in running again -- will have to pull nomination papers again in April for November's City Council election. All city councillors are up for re-election.

Turner told his former colleagues before the expulsion that whatever happens, he would not run for the district seat again and endorsed Jackson as his successor.

"Two years ago, I told Tito Jackson that if he wanted the District 7 seat, I would support him in 2013 given my decision to run for only one more term," Turner wrote in an October email to councillors. "However, over the weekend, I told him that I would support him in a special election if I am removed from the Council or in next year's regular election if allowed to stay. He indicated he is interested and ready to run for City Council either immediately or next year."