Which is why it's intriguing to see Johnson change course today, via a surprisingly spiky article in the New Statesman. There is, so far as I can tell, not one intentional gag in the entire piece – but a sizeable dollop of coalition baiting. Johnson calls for a new mantra from his party: "Labour's record was good". He outlines the "nonsense being spread by some of his political enemies". And he rails against the "Orwellian level of misinformation about Labour's record in government". It is far too tribal to properly appeal to the unconverted, but it's certainly the fieriest statement that Labour have managed since Ed Miliband's ascension to the throne.
One passage stands out as being particularly vicious. Under the sub-heading of "Us and Dems," Johnson writes:
"I find the coalition's approach objectionable on a personal as well as political level. The government spouts the importance of aspiration and the need for social mobility, but has no real-life experience of the factors involved. The lack of social diversity among the Lib Dems is even more pronounced than among the Tories. This may explain their plans on Education Maintenance Allowance, security of tenure for council houses, housing benefit, time-limited benefits and their opposition to our objective of having half of 18-to-30-year-olds in higher education."