Election 2017: Who are the key behind-the-scenes figures directing Tory and Labour campaigns?
Amid the fanfare of Theresa May's surprise call for a snap election came another shock from Number 10 as one of the prime minister's most senior advisers announced she was leaving her role.
Katie Perrior's departure as director of communications suggested she disagreed with the PM's U-turn, though she later endorsed the move for an early vote as she insisted she had always agreed not to stay in the role for an election.
So who are people left directing Mrs May and her main rival Jeremy Corbyn through their first election campaign as party leaders?
Here are a rundown of the key figures:
Sir Lynton Crosby (Conservatives)
The Australian strategist was dubbed the Wizard of Oz after masterminding David Cameron's unexpected election victory in 2015, though his mastery of the "dark arts" of campaigning were brought into question after Zac Goldsmith's divisive and unsuccessful London mayoral campaign.
Sir Lynton - who made his name in his native country's elections - had guided Boris Johnson's 2008 and 2012 successes in the capital role.
His trademark demand to "scrape the barnacles from the boat" (ignore peripheral issues) along with his so-called "dead cat" manoeuvre (distracting and directing media attention with a highly controversial stunt or intervention) have fed campaign folklore.
But after the failed Goldsmith campaign will Theresa May be as keen to take Sir Lynton's direction as gospel?
Nick Timothy (Conservatives)
The pro-Leave steel worker's son is expected to be a driving force in the Tory campaign.
He is credited with framing Theresa May's direction for a Brexit she didn't personally vote for in last year's EU referendum.
Mr Timothy's political focus is said to be seen in the PM's keenness to focus on "ordinary working people" and those "just about managing".
That influence has seen him dubbed "the man who really runs Britain" despite sharing the chief of staff role with Fiona Hill.
Mr Timothy also reportedly clashed repeatedly with David Cameron and George Osborne's inner circle - will that put him at odds with the man who directed their winning campaign two years ago?
Fiona Hill (Conservatives)
The other half of Mrs May's chief of staff double act, former journalist Fiona Hill has proven a formidable opponent to the prime minister's rivals.
That devotion cost Ms Hill her job when she became involved in a furious, and highly public, spat with Michael Gove over tackling extremism in schools.
But she reunited with Mrs May as her former boss at the Home Office took power and is tipped to replace outgoing director of communications Perrior after the election if the Conservatives are returned to office.
Seumas Milne (Labour)
Labour's director of strategy and communications mirrors his leader's left-wing views and - like Mr Corbyn - has found himself denounced for them by sections of his own party.
Mr Milne has shaped Labour's media strategy since Mr Corbyn's unexpected 2015 leadership victory but worsening polls suggest the message is not yet getting across.
The former Guardian journalist is regarded as a bright thinker but has been accused of being unable to get a foothold in the mainstream media.
Like his leader, the election will provide a make-or-break opportunity for him to get his core message to the electorate.
Andrew Fisher (Labour)
The senior Corbyn adviser is a key influence on Labour's core economic message against continued Tory austerity.
The former trade union official and parliamentary researcher authored a book about the 2008 financial crash in which he lambasted former Labour chancellor Ed Balls for his "miserable austerity-lite" economic policies.
Mr Fisher was temporarily suspended from the party following a complaint he had backed a far left Class War candidate against the official Labour candidate at the election.
But his readmission has been noted with Labour's Easter policy blitz.
The series of populist measures included putting VAT on private school fees to pay for free school meals for primary pupils, and reversing Conservative cuts to inheritance tax to provide more support for carers.