[7] He participated in the school's mountain-walking club, which went on regular excursions to Snowdonia; the original members of the grindcore band Napalm Death also took part.

[9] As a teenager, Lee suffered from ulcerative colitis,[10] which he has said caused significant weight loss and made him look "cadaverously thin".

Having moved to London and begun performing stand-up comedy after university, he rose to greater prominence in 1990, winning the prestigious Hackney Empire New Act of the Year competition.

Owing to creative differences with the rest of the cast, Lee and Herring did not remain with the group when On The Hour moved to television as The Day Today.

Throughout the late nineties he continued performing solo stand-up (even whilst in the double act Lee and Herring) and collaborated with, amongst others, Julian Barratt and Noel Fielding of The Mighty Boosh.

[12] In the same year he performed Pea Green Boat, a stand-up show which revolved around the deconstruction of the Edward Lear poem "The Owl and the Pussy-Cat" and a tale of his own broken toilet.

In 2003, he said that his favourite bands include The Fall, Giant Sand and Calexico and that he listens to "a lot of jazz, 60s and folk music but I really like Ms. Dynamite and The Streets".

A profile in the Financial Times in 2011 stated Lee did not want to alienate his audience in exchange for quick money by such appearances, as working as a stand-up had been the only thing that had generated reliable income for him.

[22][23] Lee wrote a negative review of the show in Time Out in which he described himself as "fat" and his performance as "positively Neanderthal, suggesting a jungle-dwelling pygmy, struggling to coax notes out of a clarinet that has fallen from a passing aircraft".

[26] Lee frequently uses negative reviews on his posters in order to put off potential audience members who are unlikely to be fans of his comedy style.

[33] In September 2020, Asian Dub Foundation (a political band from London who had a Top 40 hit with "Buzzin'" in 1998) released a song called "Comin' Over Here", which was based on a sketch from Lee's Comedy Vehicle about the UKIP party leader Paul Nuttall.

[34] In December 2020, Lee teamed up with Asian Dub Foundation to release a video for the song, which was at that time part of an internet campaign (in the style of LadBaby, Rage Against The Machine et al.) to get the record to number one in time for the chart published by the Official Charts Company on 31 December 2020, thereby making the record the 'Brexit Day Number One'.

[40] In 2022, Lee removed his material from Spotify because it refused to stop The Joe Rogan Experience spreading COVID-19 misinformation on its platform.

Director Wils Wilson said "The Porter is dark, funny, edgy, political, clever, a truth teller - Stewart is all of these things, and straight away I knew I wanted to ask him to write to.

[45][46] Lee's influences include Ted Chippington, Arnold Brown, Norman Lovett, Jerry Sadowitz, Simon Munnery, Kevin McAleer and Johnny Vegas.

He also employs meta-humour,[49] openly describing the structure and intent of the set while onstage, and abolishing the illusion of his routines as spontaneous acts.

[50] Lee's delivery uses various onstage personae, frequently alternating between that of an outspoken left-wing hero and that of a depressed failure and champagne socialist.

In an ironic manner, he often criticises the audience for not being intelligent enough to understand his jokes, saying they would prefer more simplistic material, or enjoy the work of more mainstream "arena" comedians such as Michael McIntyre or Lee Mack;[7] He will also scold them as a bias-seeking "liberal intelligentsia".

Lee caused controversy on his If You Prefer a Milder Comedian tour with a routine about Top Gear presenter Richard Hammond.

I mean, you can't be on Top Gear, where your only argument is that it's all just a joke and anyone who takes offence is an example of political correctness gone mad, and then not accept the counterbalance to that.

[53]In an Observer interview, Sean O'Hagan says of the Hammond joke that Lee "operates out in that dangerous hinterland between moral provocation and outright offence, often adopting, as in this instance, the tactics of those he targets in order to highlight their hypocrisy".