Oven element glowing white hot

I’ve just noticed that the lower in our oven is glowing white hot – as in, it looks as if someone’s put a light bulb under the lower plate of the oven cabinet, and there a couple of glowing red-hot hotspots on that panel above parts of the element.

(Yes, it’s now turned off and we’re only using the upper element until this is figured out)

What would cause that, and will simply replacing the element fix it?

(It’s a Britannia oven, not white sure what model)