Maybe - just maybe - its the switch that controls the element.
http://www.rangemaster-spares.co.uk/cooker-oven/oven-function-selector-switch-ego-4202900027/product.pl?pid=948016&path=156166
http://www.rangemaster-spares.co.uk/cooker-oven/energy-regulator-ego-5055023010/product.pl?pid=1214145&path=156166
You may need to do a bit of digging and thinking.
XXX, May 2016