First start of the day

Hi,
One first start of the day my 2005 TD4 fails to turn the starter motor all I get is a clicking sound not sure if this clicking is form inside the dash or the starter solenoid. After several attempts the car starts and will be ok for the rest of the day. Seems worst on cold days?
The battery is only 6 weeks old and has been checked so could it be starter contacts/ solenoid (easy fix) or possibly a problem with the immobiliser. Any one else had this.
Cheers in advance. Forgot to say its a manual so that would rule out problems with inhibitor.

Had this on another car before, what I did to find the problem was to wait till I had a "click" problem and touched a test lead from the battery + direct to the starter solenoid - when that spun the engine over OK first time I knew the problem was the starter solenoid relay and the solenoid itself was fine.

Hi you can get a solenoid repair kit if its a denso , from repairkitsUK for £12.15 c/w fitting guide

Update
Freezing cold this morning (-2) put key in and just got a single click for each turn of the key (after waiting for glow plug light to go off) Removed key and re-inserted started on first turn, so now thinking transponder/ key ??.
Thanks for info on repair kit.