Which topic stumps Tony Blair most often? The reform of public services? Iraq? Top-up fees? Asylum and immigration? On these, he can usually manage fluent answers. But not on his eating habits.
As a guest on a Sheffield radio phone-in the other day, Blair was asked to name his favourite sandwich. As a political question, this beats some of the guff he is asked at his monthly press conferences. Or even most of what he is asked at Prime Minister's Questions. He cannot avoid the question or get away with half-answers. And any answer will be loaded with political symbolism. After all, the proverbial beer and sandwiches with union leaders dogged every Labour leader before Blair.
So the PM could opt for the proletarian bacon buttie, albeit without brown sauce. He could claim chicken tikka, with its gentle nod to an imperial past and a firm statement of a multicultural present and future. Or he could confirm the Islington stereotype and suggest Parma ham with pecorino cheese on toasted ciabatta. No wonder he paused.
William Hague, as Tory leader, once called called Blair a hypocrite on food. The PM had told the Labour Party's magazine that his favourite food was fish and chips and that he got a takeaway whenever he was at home in his constituency. Yet in the Islington Cookbook (yes, such a book does exist) his choice was "fresh fettuccine garnished with an exotic sauce of olive oil, sun-dried tomatoes and capers".
These different answers (to different audiences) demonstrate the political symbolism we attach to food. Food production and distribution is an increasingly hot political issue. Should Blair now answer "organic fettuccine", or "fish only from renewable stocks"?
So what was Blair's favourite sandwich? His answer was clever - the declasse BLT. Although some questions do remain. What of the vegetarian vote? And what type of bacon and tomato?
Anthony Vigor is a researcher at the Institute for Public Policy Research