They are called Schuko plugs which is a short form of the German term Schutzkontakt (literally: protective contact), which indicates that plug and socket are equipped with protective-earth contacts (in the form of clips rather than pins). Schuko connectors are normally used on circuits with 230 V, 50 Hz, for currents up to 16 A. So now you know.
And yes,the kettle arrived with the UK 3-pin lead although the picture in the manual shows the European variety. Um. Never mind, I'll pick up a replacement lead when in town next. Much better than using an adapter I think because the sockets in the van are at the front of the kitchen unit so an adapter stuck in one of those will make walking by a bit tricky.