'The programme taps into disillusionment with politics, which presents opportunities for publicity from women's weeklies and tabloids to broadsheets,' said Johnson.
The Amazing Mrs Pritchard – which features ex-Tory minister Michael Portillo – will also be promoted via a spoof website for the eponymous heroine's fictional political party, the Purple Alliance.
Further briefs include Tiger Aspect's drama Murphy's Law for ITV, and upcoming Channel 4 programme Gold Plated.
Johnson spent five years at the BBC, where he was head of publicity for drama before his role was broadened to include factual programming.
Johnson is also handling publicity for actress Anna Friel and Tracy-Ann Oberman, who played Chrissie Watts in EastEnders.