The Iraq war and energy crisis were the core of Newman's set, him presenting a scenario of a continuous Western foreign policy since the early 20th century centred around middle-eastern oil. Throwing together facts from the Mesopotamian campaign of the first World War, to a paper on "Oil Fields as a Strategic Target" published in 1973. (Which I can't find with google, cold-war jargon often used "Strategic" as a euphemism for use of nuclear weapons, so it might not be directly relevant). One interesting fact he threw out was the energy balance of US farming, that's apparently shifted by several orders of magnitude over the past 60 years, from something like 1000 calories produced per calorie used to 2000 calories used per calorie produced.
The set however was superbly constructed, between the heavyweight (but hilariously presented) doom-mongering, there were frequent segues into quick gags and peculiar flights of fancy, including a party-piece of singing "Rock around the Clock" in arabic.
Mark Thomas concentrated far more on domestic politics; Labour party authoritarianism, playing on class differences, absurdities of reporting and spin of the "War on Terror", and frequent anecdotes of his activism (such as putting a sign on Geoff Hoon's constituency office reading "Al-Qaeda Recruiting Centre"). The longest set of anecdotes was around his trip to a London arms fair, and the interactions with his appointed escort, presented as being a living archetype of the upperclass Nice-But-Dim ex-military type. Overall Thomas' set was much faster paced, more frequent laughs, but less of a carefully constructed intellectual argument than Newman's, the contrasts in style and similar but different subject matter worked quite well.