Sources at the agency confirmed Blackie’s departure but declined to comment further.
It is understood that Blackie’s responsibilities have been taken over by Sam Jeffers, one of the directors in the agency’s London office.
Industry sources have suggested that Blackie’s departure was due to dischord with Blue State Digital’s US headquarters. Blue State Digital declined to comment on the suggestion.
The agency recruited Blackie from Blue Rubicon in 2011, putting him in charge of its UK-based operations and its European expansion plans. It started working for the Labour Party in March this year.
Blue State Digital was co-founded by Joe Rospars and Jascha Franklin-Hodge in the US and is known for its pioneering digital work on Barack Obama’s first presidential campaign.
At the start of 2011 the agency was bought by marketing services giant WPP.
Blackie could not be reached for comment at the time of publication.