The Diary’s hopes of naughtiness were raised by a fortuitous eve-of-departure article in the Daily Telegraph highlighting Zurich’s nightspots and Samp;M bars, which was widely circulated among the party.

“You can find whatever you want, from bottle to brothel, under the watchful eyes of Portuguese mafiosi. It is sleazy but fun, and the bars are cheaper and generally illegal,” enthused the reporter. However the itinerary - coach departing at 7am - rather put paid to Seven Go Mad in Toblerone-land. They were there to inform their inquiry into the future role of headteachers. Zurich canton, it seems, does without them.

It was a packed schedule, but rather novel for the MPs, who are usually met by the head and whisked around the school, stopping at the trophy cupboard. Instead they sat on child-sized chairs and sat through lessons, listening, until the bell rang. Joe Benton, MP for Bootle, was gratified to find he could keep pace with the 13-year-olds’ geometry lesson. “And it was in German,” he beamed.

The group may not have strayed into the seamier side of the city, clutching their official plastic packages of pocket money (brown envelopes, mysteriously, are out) but they did encounter Zurich’s zanier side - 800 wacky life-sized models of cows intended to “kick off a prosperous and positive attitude in the city”. Unfortunately, only the Lib-Dems’ Don Foster dared volunteer to be photographed with one.

And all school trip arrangers know, there’s always one. Prize for giving the clerk the biggest headache went to Nick St Aubyn, who first of all lost his aeroplane tickets and then, perhaps in his haste to buy chocolates for his five children before departing, left his car keys and credit cards in the hotel.