Deans, who retired from the Daily Mail in January after 16 years, said the position was one of a number of offers he had been considering.
The political lobby veteran, who will manage all press office work, said: 'This is not a job I have taken for political reasons. I'm not saying what my political allegiances are. I have taken this job for professional reasons. I liken the position to that of a news editor.'
His appointment is the latest in a series of changes within the party's PR function following the general election defeat in June 2001.
Head of media Nick Wood, to whom Deans reports, replaced Amanda Platell in the top PR post in September, when Iain Duncan Smith was appointed as leader.
Another change saw the promotion of Mike Penning, Duncan Smith's press secretary, to the post of deputy head of news and media, with a special responsibility for briefing the parliamentary lobby.
Deans replaces Paul Larter, an Australian former journalist who has moved back to his home country.
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