The casualties include director of strategic communications Paul Baverstock, media director Nick Wood and head of broadcasting Nick Longworth.
Vanessa Gearson, the whistleblower in the 'Betsygate' affair is also believed to be leaving party HQ.
Mike Penning, Iain Duncan Smith's former press secretary, who was last year selected to fight Hemel Hempstead for the Tories at the next general election, is also out.
The extent of the cull, which was handled by the newly appointed joint-party chairman Liam Fox, took even Tory staffers by surprise.
As PRWeek went to press, Central Office confirmed media reports of the changes.
Baverstock joined the Tories early this year from a role as chief operating officer at Bell Pottinger Communications.
Howard, who replaced Duncan Smith as leader last week, has since demoted half the front bench team and changed most of the survivors' jobs.
Wood, a former journalist, served as head of news under both Duncan Smith and his predecessor William Hague.
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