But Stuart Bell is far removed from that stereotype. He is 27 - although he could pass for younger and admits to getting ‘ID'd' occasionally when buying alcohol - sports a mop of swishy pop-star hair and has a warm, boyish manner.
He seems to have a refreshingly un-starry upbringing, having lived in Croydon or Purley all his life, and listing support of Crystal Palace FC and watching Newsnight as among his hobbies.
Bell has a fascinating insight into McCartney and Heather Mills' messy marriage collapse - but, as PRWeek had been politely forewarned, discussion of the former Beatle is absolutely off the agenda.
But despite declining to comment about McCartney, who he has represented since 2004, he cannot escape the connection for even a moment.
In the lift of his office, he bumps into a former acquaintance, who laughs as he greets him with ‘How are you coping?'. Next, our photographer asks Bell to ‘give my regards to Sir Paul'.
Being PR man to a national treasure in the midst of a personal crisis is a difficult role to escape. Bell currently carries three mobile phones and the inevitable BlackBerry. He concedes it has been a ‘long summer' and ‘a learning experience' - but that is all he will say.
As well as advising McCartney, Bell also works for Ronan Keating, Westlife and mobile phone company Nokia.
He started his career making tea during work experience at RCA Records, abandoning his A-levels to join its press office full-time for two years. A genuine music nut, he plays guitar and says he is influenced by The Killers and Razorlight.
He says: ‘Some people are blatantly working in the music and PR industries because they want to hang out with famous people - they are obsessed by the smallest celebrities and will say "Last night I had dinner with so-and-so from Big Brother 2", and you think, so what? Last night I went to watch the football with my best friend from school. I think that's a lot more interesting.'
Bell joined The Outside Organisation in 1999, when the company had just a handful of staff (now in its tenth year, the agency is 46-strong). He works closely with its well-known CEO Alan Edwards, who he says has taught him a great deal.
‘Alan always reminded me to ensure that I returned every phonecall, every fax, every email - to remember that I was providing a service to the media. They were little things, but it's easy for some people to lose sight of them,' he says.
What is more, he says he was encouraged to build personal relationships with journalists and to talk to the tabloids on a daily basis.
‘Otherwise you feel like tabloid journalists are not human beings and every time they leave a message you're terrified,' he explains.
Sunday Mirror assistant editor (showbiz) Ben Todd has known Bell since 1999, when the latter was plugging the then unknown girl band Atomic Kitten.
He describes Bell as ‘a fantastic guy, kind, cool under pressure and one of the best in the business', adding: ‘He has never become pompous or arrogant, and he never fell into the showbiz traps of partying too hard or believing his own hype'.
Having such relationships in place must help Bell with McCartney's current situation.
Bell says: ‘You forge relationships and then suddenly you start getting calls the night before a story runs with journalists saying "we just want to let you know we're running a story about your client" - and then you have time to react or to deal with it.'
Bell will no doubt receive many such calls before the year is out, but he believes he has the contacts and the character to deal with them adeptly.
CV - Stuart Bell
2002 - Director, The Outside Organisation
2001 - Senior press officer, Polydor Records
1999 - Press officer, The Outside Organisation
1997 - Press assistant, rising to regional press officer, RCA