Ensemble Dark Horse: As with the main series, Jamie "The Crossest Man in Scotland" McDonald steals every scene he's in despite being only a secondary character.
Judy: "I have not leaked anything, and I'm not going to be intimidated by some Cro-Magnon Scottish dwarf!" Jamie:(furious) "Are we exploring personal boundaries, youFUCKING STUCK UP— (answering mobile) Hang on, hang on. Hi, hi. Listen, I'm in the middle of something, can I ring you back? Ta. (hangs up) Where was I? Oh yeah: YOU FUCKING STUCK UP TOFFEE PUDDING BITCH."
General Miller also counts, for various reasons that include being the Only Sane Man in the Pentagon, not being afraid of Malcolm, and he's played by James Gandolfini.
Jamie to Judy: "I'm quite aroused by the idea of giving you a long... hard... disciplinary hearing."
Followed by a nice moment for Judy, when she actually manages to shut Jamie up by coolly remarking that she would quite enjoy the "big... fat... compensation payment" she would receive as a result. The look on Jamie's face after this indicates that he just might need to go home and have a wank.
Jamie explains the uselessness of builders by remarking that you never see films in which the hero is a builder. "Bat-Builder? Spider-Builder? That's why you never see a superhero with a hod!" One of the Big Bads in Jonathan Hickman's Avengers run was an alien race called the Builders.
Ho Yay: "Fuck the 'nibbles', what was with the homoerotic tension?" Good question, Toby:
Malcolm and Jamie's transatlantic phone calls: "Missing you loads..." "...I love you."
"You may want to slip into your negligee..." Malcolm interrupts Simon and Toby's quiet night in.
There's a lot of space on the bed, but Toby and Simon are cozily arranged on one half of it as they watch the shark documentary. In their pants.
Forget that, an earlier shot shows there are two beds.
After their discussion in Michael's office, Malcolm even ends up patting Simon on the crotch.
A few people comment on how Chad's eagerness to kiss ass with his male superiors has a curiously homoerotic edge, but it really becomes apparent when, in an effort to get in General Miller's good books, he ends up complimenting the General's testicles. The General, unsurprisingly, is nonplussed.
Toby's quote was provoked by Sir Jonathan Tutt, whose pleasant attempts at small talk with Malcolm, Simon and Toby seems to somehow become a form of really inept flirting with Malcolm. ("You just put your lips together and you blow!")
"I'm not dancing with you on this Malcolm!"
Several characters insult Malcolm by way of claiming that he's gay. He doesn't actually deny it (and then there are those phone calls to Jamie mentioned above...)
The above phrase gained renewed popularity among students in 2017 in the form of "When you thought your assignment was going to be easy peasy lemon squeezy but it's actually difficult difficult lemon difficult."
Misaimed Fandom: The Thick of It has so many fans in Whitehall that the crew were given a very rare opportunity to film there. That's the actual Number 10 in the film's opening scenes (which at the time of filming was undergoing some restoration work, hence the construction).
Similarly, some Pentagon generals rather liked it, both because of James Gandolfini, who apparently has a following there, and because they appreciated Gen. Miller's only sane man tendencies (not to mention the fact that even though Miller opposes the war, with sound reasons given (not just because he's a dove) but when war is declared, his immediate priority is providing leadership to his soldiers (although this is depicted at least partially as being an act of moral cowardice on his part as well).
Malcolm's Bastard Understudy, Jamie, pushes Michael Rodgers MP over another Horizon: "Aww, don't cry."
Never Live It Down: General Miller's relationship with Karen Clarke has been largely defined by a one night stand he can't even remember from 20 years ago. Apparently she hasn't left him in peace since.
Nightmare Fuel: There's something genuinely disturbing about Jamie eagerly forcing Michael to delete the arguments against the war.
One-Scene Wonder: Steve Coogan is in the movie for probably five minutes at tops. He's nevertheless one of the best things in it, which is pretty impressive considering what he's up against.
Tear Jerker: The entire Downer Ending. Malcolm ended up doing the dirty work of a man he swore he didn't work for; After repeatedly waffling, Simon's career is all but finished when he's sacked rather than being able to resign to make a statement; Clarke's resignation loses its power when Miller refuses to do so; Liza's working for a man concerned with which movies are on a soldier's approved roster; and you have to even feel bad for the selfish and self-righteous Toby, whose career is over before it even begins and he leaves quietly when the new aide arrives. And everyone has to live with the inevitable war that's going to happen, and one Miller knows no one is prepared for.
For all of Simon's cowardly flip-flopping and refusal to take a side, his outburst that he's frustrated about being forced into an inevitable position where he's sending boys off to war, which is the exact opposite of what he wanted to do when he got into office.