In a significant if not unexpected development, members of the late Sen. Edward Kennedy’s (D-Mass.) family will endorse Massachusetts Attorney General Martha Coakley (D) to fill his seat on Thursday.

The Coakley campaign announced in a release that Kennedy’s widow, Vicki, nephew Joe Kennedy, a former Massachusetts congressman, and great nephew Joe Kennedy III will endorse the Democratic nominee tomorrow in an event in Medford, Mass. Interim Senate appointee Paul Kirk, a close associate of Sen. Kennedy and his family, will also throw his support behind Coakley.

Both Vicki and former Rep. Joe Kennedy were approached about running for the seat but ultimately passed.