Dominic Cummings has made his presence felt in Westminster since he was appointed as a senior advisor to Prime Minister Boris Johnson in July and its not just lawmakers that have noticed.
"It is Dominic Cummings and you playing games with Parliament, playing games with the people of the United Kingdom and all the people who are entitled to vote in this country. You are playing games," an angry member of the public yelled at Johnson in front of TV crews on a Leeds street on Thursday.
In his uniform of a creased white shirt, the media has labelled him everything from the "architect of a no-deal" to "Rasputin" and "political Svengali".
Now, Ken Clarke, a veteran of the House of Commons, has gone as far as to say Cummings is "running the country".
He told Channel 4 News that there is a belief Cummings has a “belligerent” attitude.
“The very wide and almost universally held theory in the Palace of Westminster by ministers and backbenchers [is] this chap Cummings is really running the government,” he added.
Who is the man supposedly pulling the strings in the Johnson camp?
Cummings, originally from Durham, is the son of an oil rig project manager and a special needs teacher. He graduated with a First in Ancient and Modern History from Oxford University in 1994.
The title of "Brexit architect" does have some truth — he coined the Vote Leave slogan “take back control” and was the mastermind behind the now-infamous £350m-for-the-NHS slogan that was splashed across the side of a bus.
Indeed, the political advisor and strategist served as the campaign director of Vote Leave.
In fact, this was not his first experience in campaigning for a eurosceptic theme. Cummings was campaign director at Business for Sterling, the campaign against the UK joining the Euro, from 1999 to 2002.
Nor is it his first time at the side of Conservative politician, acting as director of strategy for Iain Duncan Smith for 8 months in 2002 and working for Michael Gove from 2007 to January 2014.
Despite his links to the Conservative Party, Cummings has never joined a political party himself.
In a profile published by Conservative Home in 2014, author Andrew Gimson called him "exceptionally intelligent, without being exceptionally steady," adding: It has been said of Cummings that “you underestimate him at your peril”.
Gimson also remarked that it was rare for a special advisor to attract any attention, "let alone the amount he was getting".
Cummings is continuing to draw the spotlight, last week raising questions from MPs as to why he was granted a security pass for the Palace of Westminster, despite having been found in contempt of Parliament.
While Britain's departure from the EU remains uncertain, one thing we can be sure of is Johnson's advisor will be making his presence known.