The very mention of the names Cummings and Milne is enough to prompt fear and loathing among their detractors, and unquestioning loyalty from their supporters.
Aside from both having been privately educated and having gone to Oxford, the two men also share an ability to provoke a reaction and become the centre of controversy.
They are the power behind the thrones of the Prime Minister Boris Johnson and Labour leader Jeremy Corbyn.
On the way out?
Yet at a time when their masters are fighting for control of the country, their own days may be numbered, according to recent media reports.
In one story, Alan Johnson, the former Labour home secretary, said that Cummings is seen as "the puppet master" behind Boris Johnson and that "his days are numbered".
He accused the former Vote Leave director, who is Boris Johnson’s de facto chief of staff, of letting his sudden celebrity status go to his head.
And referring to the time Cummings spent as an adviser to Michael Gove when he was education secretary, he said: "No one else has come in as a special adviser to the Prime Minister who has been such an abject failure in his previous department."
For the avoidance of doubt, Alan Johnson added: "He’s on his way out."
The remarks were made at an event at the Cheltenham Literature Festival last Saturday to discuss the role of special advisers in government.
The monster in Downing Street
Johnson was sharing a platform with Katie Perrior, former Downing Street comms director under Theresa May and co-founder of iNHouse Communications.
Referring to speculation that Cummings is briefing journalists as an unnamed Downing Street source, she commented: "Is Dominic Cummings speaking on behalf of the Prime Minister or is Dominic Cummings speaking on behalf of Dominic Cummings? That’s the concern."
Perrior added: "We have created a monster, as it were, inside No 10 whether we like it or not, who the media will go to if they are not getting anything out of the Prime Minister."
And earlier this week The Daily Telegraph ran a story, based on unnamed sources within Labour, on how Milne finds himself at number two on a sinister sounding ‘list’ of people that the shadow chancellor John McDonnell wants to see replaced.
Milne, a former Guardian columnist, has been the Labour Party’s director of strategy and comms since October 2015.
So, are rumours of the demise of Britain’s two most powerful political advisers exaggerated or are their days numbered?
Cummings has "real ability"
Perrior (above) told PRWeek that off the record briefings from the heart of government can take on "a life of their own and then you have to feed it all the time".
She said: "I strongly feel, as former director of comms at Number 10, that you should speak on behalf of the Prime Minister and the Prime Minister only. In the past it has not really ever served us well in the long run to have two voices out of Number 10."
Perrior does not think that Cummings is "some kind of evil monster who’s going to ruin everything".
She added: "I think that he has some real ability and I sometimes feel that people paint him unfairly."
Cummings is "working in extreme conditions and very difficult circumstances that are not normal and so it’s easy for people to have a pop".
Perrior commented that the "jury is out" when it comes to whether the UK will be able to leave the European Union "without any huge distress" and the chances of the Conservative Party winning the next general election.
She said that Cummings has "always been incredibly nice talking to me" and that "he inspires incredible loyalty among a large number of people I know".
Perrior remarked: "If someone can attract that much loyalty from people that I know and respect, there must be something about him."
When it comes to Cummings, he already has an exit strategy in place. He had only committed to working at Number 10 until the end of this month, as he needs to have a major operation that has already been postponed to allow him to pursue his dream of seeing Britain leave the EU by the end of October.
Mark Glover (above), chief executive, Newington Communications, commented that some people are making "political mischief" when it comes to speculating that Cummings will go, as he was never planning to stay at Number 10 for an open-ended period of time.
As for Milne, "there is no doubt that John McDonnell is trying to strengthen his grip and there have been moves against some of Corbyn’s leadership team".
He added: "I doubt very much this close to an election that Seumas will be particularly worried about his position but I think some of this manoeuvring is about what happens after an election."
Providing cover for their political masters
The fact that speculative stories are being run about their potential departures reflects the "growing importance of the most senior adviser to a political party’s leader", according to Emma Petela, co-chair of the PRCA's Public Affairs Board and director at GK Strategy.
"While it is true both Cummings and Milne wield significant power over the direction of party policy and dominate political reports and media coverage, neither have been too concerned about the vast array of criticism they garner daily on behalf of their leaders," she said.
"While this in turn is creating positions that are largely viewed as being too powerful, they remain somewhat protected by the needs of their leaders to have high profile ‘shields’."
Petela (above) remarked: "Both advisers remain pivotal to the success – or failure – of both leaders. And with the current leadership of both parties prone to making mistakes, we are unlikely to see either losing their senior advisers this side of a general election."
Time running out?
Gill Morris, chief executive, DevoConnect, described Cummings as "a huge risk taker" but added that "gambles don’t always pay off".
She said: "I very much doubt he can sustain his position of master puppeteer at No10 in the long term."
As for Milne, she commented: "Jezza looks increasingly isolated and Seamus could easily be collateral damage in the short term."
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