On Tuesday he was forced to apologise to Parliament after giving a misleading impression in a TV interview over his role in the disputed resignation of DTLR comms director Martin Sixsmith.
Granatt has been called to give evidence to the House of Common's public administration select committee, which has long been concerned about the relationship between ministers, civil servants, particularly press officers, and special advisers.
At a hearing due to take place on 28 February, committee chair Tony Wright MP is expected to grill Granatt on what action is going to be taken to improve the situation.
Speaking on BBC Radio 4's World at One last month, Wright said, 'The whole communications side of a government department seems to be in a shambolic state.'
Also due to speak at the hearing are Professor Stuart Weir of the Democratic Audit and BBC political corespondent Nicholas Jones.