House Speaker Salvatore DiMasi plans to endorse Sonia Chang-Diaz in her general election race against state Sen. Dianne Wilkerson Tuesday morning.

[img_assist|nid=192|title=House Speaker Salvatore DiMasi (D-Boston)|desc=|link=none|align=left|width=136|height=143]

Sources close to the speaker told PolitickerMA.com Monday night that DiMasi, who backed Wilkerson last month in her primary against Chang-Diaz, will endorse Chang-Diaz at a Democratic Party unity event Tuesday in Boston's South End.

Chang-Diaz defeated state Sen. Dianne Wilkerson in Suffolk County's 2nd District Democrat Primary on Sept. 16. Since then, Wilkerson, of Boston, has vowed to run a write-in campaign in the general election against Chang-Diaz, of Jamaica Plain.

DiMasi becomes the third major Bay State politician to switch his allegiance from Wilkerson to Chang-Diaz. Gov. Deval Patrick (D-Milton) and state Senate President Therese Murray (D-Plymouth) also backed Wilkerson in the primary and have switched to supporting Chang-Diaz since she won the Democratic primary.

Check out PolitickerMA.com's running list of who Wilkerson's primary supporters are backing in the general election here.