Any communications strategy devised in Downing Street also has to compete with noisy agendas elsewhere in the party.
What really* happened when Crosby and Cameron talked.
But why didn't the PM answer himself?
Both parties’ interests lie in the Conservatives' campaign strategist sticking around. He can't win over the liberal voters the Tories need for victory.
The Tories say Labour are wasting their time attacking the PM's campaign strategist. Well, they would, wouldn't they.
Whether Cameron is prepared to say whether he discussed tobacco policy with his campaign strategist is turning into a test of his honesty and integrity.
Five days after the government postponed the introduction of plain cigarette packaging, the Tories' campaign strategist remains the story.
Labour and Conservative MP Sarah Wollaston argue that the Tory strategist, whose company has close links to the tobacco industry, is to blame for the decision.
The Conservative MP criticises the PM's U-turn and says "we should all be aware" of Lynton Crosby's links to the alcohol and tobacco industries.
After minimum alcohol pricing and plain cigarette packaging are dropped from the Queen's Speech, Labour and Tory MPs point to the election chief's connections.