To think the unthinkable, are we now getting towards the thin end of The Thick of It? The show remains unchallenged as the most bilious, urgent comedy on television. No argument there. It coruscates, it eviscerates – even a thin Thick of It does all those aggressive things to the body politic that satire should. But is there now the merest hint, just the faintest smidgin, of weariness, of heaving itself once more into the ring to land a few more blows on the clapped-out mob currently downing dregs of Pinot Grigio in the Last Chance Saloon?