http://www.caa.co.uk/docs/33/CAP452.PDF also refers. I was looking to see if Ground use by engineers was excepted (like glider pilots)...
Apparently we're all law breakers. Best I refuse anyfurther ground testing!
Apparently Ofcom do need to issue cert.
One would think that CAA audits of all EASA 145 company procedure would check such a thing!
I have worked for some large well known airlines that issue Engine Ground Running approval quite happily without this legal requirement...