Car not starting

[Mu54_1]

Hi there,
After a long drive I parked my car up with no problem came back the next morning and would not start. Mechanic came and replaced starter to no avail battery is reading fine and when diagnostics were run came up with starter relay error however he replaced the starter relay near the steering column but still would not start, he said it was an electrical issue. Any ideas or help would be much appreciated.
Thanks

[Retali]

Dont wanna sound like a dork, but did you check the fuses for the relay ?

[iichel]

no crank, no start, something else happening?

[Retali]

Could an immobilizer mulfunction on his key ?