Where Power Lies: Prime Ministers V. The Media, by Lance Price, is an account of how successive British prime ministers have courted the media, and how their efforts were reciprocated. Price was one of Tony Blair's most senior 'spin doctors', thus his analysis is hardly objective. He presents an insider's view of Blair's PR strategies, though a more detailed account can be found in Campbell's diary The Blair Years.
Famously, The Sun declared "IT'S THE SUN WOT WON IT" on 11th April 1992 after that year's general election, implying that the newspaper had helped the Conservatives win the election. Anecdotally, it seemed that many voters simply wanted to give the Conservatives another chance, and The Sun's campaign arguably had little direct effect. Likewise, when The Sun announced its support for Labour in 1997, and swung back to the Conservatives in 2009, it was probably reflecting - rather than influencing - the attitudes of its readers.
Prime ministers take the media extremely seriously, however. Press barons from Alfred Harmsworth to Rupert Murdoch have bargained behind closed doors with prime ministers and cabinet ministers, securing policy commitments in exchange for favourable editorials. The Euro-scepticism of The Sun and the Daily Mail, for example, surely influenced Tony Blair's reluctance to push for British membership of the European single currency (though Gordon Brown's opposition was presumably a more substantial factor).
Sustained newspaper campaigns can have a cumulative effect, as when the News Of The World and other Sunday tabloids revealed the infidelities of numerous ministers in John Major's government, exposing the hypocrisy of Major's "back to basics" pledge. More recently, The Daily Telegraph's long-running revelations about MPs' expenses led to fundamental political reforms last year. Price has interviewed other Downing Street staff to provide an account of Gordon Brown's media relations; as in Andrew Rawnsley's The End Of The Party, the focus is on Brown's combative personality.