I have now had a good luck at all of the areas raised.
The head earth bolt did not appear to be 100% tight but tightening did not cure the problem. I Checked the main earth to the block and that was fine. I also checked both keys and disconnected and reconnected everything the in the electrical box. It's still the same. I have it booked into the garage on Monday so hopefully they can find the problem.
I'll provide an update next week.