Question: Who wrote The Unauthorised Biography of David Cameron and a politician?

Context paragraphs:
Michael Ashcroft: Michael Anthony P. Ashcroft, Baron Ashcroft, (born 4 March 1946) is a businessman, and politician.  He is a former deputy chairman of the Conservative Party.  Ashcroft founded Michael A. Ashcroft Associates in 1972 and is the 74th richest person in the UK, as ranked by the "Sunday Times" Rich List 2015, with an estimated fortune of £1.32 billion.

From the Cradle to the Grave (DVD): From The Cradle To The Grave - The Unauthorised Biography is an unofficial Cradle of Filth biography that covers the band's history up until the 2000 album of "Midian".  It features two of the band's key members when Cradle of Filth debuted, as well as the band's original recording studio, Cacophonous Records.

Comrade Corbyn: Comrade Corbyn: A Very Unlikely Coup is a 2016 book by British journalist Rosa Prince, published by Biteback Publishing.  It is an unauthorised biography of the Leader of the British Labour Party, Jeremy Corbyn.

Premiership of David Cameron: The premiership of David Cameron began on 11 May 2010 when Cameron accepted the Queen's invitation to form a government.  This occurred upon the resignation of Cameron's predecessor as Prime Minister of the United Kingdom, Gordon Brown.  While serving as Prime Minister, Cameron also served as First Lord of the Treasury, Minister for the Civil Service and Leader of the Conservative Party.

Altitude 360: Altitude London is a collection of venues in the 387 ft -high Millbank Tower, a skyscraper in Central London.  Covering over 30000 sqft , of event space.  Altitude 360 London, along with The River Room London, The MillBank Cinema & Media Centre and The View Collection make up London's largest riverside venue as well as London's largest venue located in a skyscraper.  The concept and design was the brainchild of Hong Kong born entrepreneur Justin Etzin who is The Global Brand Owner.  The venue was opened in three phases, with the first phase opened in September 2007 by the then Leader of the Opposition David Cameron, the second phase was opened by Mayor Boris Johnson and the final third phase opened in May 2010 by Prime Minister David Cameron.

Piggate: "Piggate" refers to an uncorroborated anecdote that during his university years former British Prime Minister David Cameron put a "private part of his anatomy" into a dead pig's mouth as part of an initiation ceremony for the Piers Gaveston Society.  The anecdote was reported by Michael Ashcroft and Isabel Oakeshott in their unauthorised biography of Cameron, "Call Me Dave", attributing the story to an anonymous Member of Parliament who was a "distinguished Oxford contemporary" of Cameron's.  Extracts from the book were published in the "Daily Mail" on 21 September 2015, prior to its publication.

Mohan Deep: Mohan Deep (born Mohan Kishinchand Chandirramani in 1948), is an Indian writer.  He has written multiple books on Bollywood film personalities, including the books: "The Mystery and Mystique of Madhubala", "It's My Life" (novel), "Simply Scandalous: Meena Kumari", "Eurekha!  – an unauthorised biography of Rekha", etc.  In recent years, he has focused on writing fiction.  Two of his novels are "The Five Foolish Virgins" (2013) and "Color Me Rich" (2016)

Call Me Dave: Call Me Dave: The Unauthorised Biography of David Cameron is a 2015 book by Michael Ashcroft, a businessman and Conservative peer, and Isabel Oakeshott, a political journalist, about the then Prime Minister of the United Kingdom, David Cameron.  The book, excerpts from which were published in the "Daily Mail" prior to publication, received significant media attention, particularly relating to allegations made about Cameron.  It is published by Biteback, a company in which Ashcroft has a majority share, run by political blogger Iain Dale.

Radiant Baby: Radiant Baby is a musical about Keith Haring, who was an artist and social activist in New York City.  The music was composed by Debra Barsha, with lyrics by Ira Gasman, Stuart Ross, and Debra Barsha.  It was suggested by "Keith Haring: the unauthorised biography" by John Gruen.

David Torrance (journalist): David Torrance (born 7 August 1977 Edinburgh, Scotland) is a British political journalist, author and contemporary historian.  Torrance is best known for his unauthorised biography of Alex Salmond and his political commentary for STV and BBC.

Supporting paragraphs: Call Me Dave Michael Ashcroft
Answer: Michael Ashcroft