Belling DB 90 Range Cooker fault

The small (1.2kW) front fastlite element has stopped cycling (turning on and off automatically) on my 2 year old Db90 and remains on at full pelt regardless of control position (except off of course!). I’m guessing a thermostat has packed up but short of stripping it just to check out the arrangement inside, I don’t know what part I’m looking for.
Is the ‘stat (or thermal limiter or whatever) incorporated in the control switch or is it a seperately available item? can someone give me a part number?

Also, where might I source the relavent part? None of the spares websites I’ve seen list the Db90.

Incidentally, this cooker replaced a Tricity Soverign about which I see much discussion here. I too suffered from the oven control problem but as an electronics engineer by training I worked out what caused it. The fix is simple for someone with basic skills (someone who is competent enough to get the controller out without breaking it can easily repair it) and I will post it seperately for anyone who might be interested.