Starter turns engine 1 rev or so then just stops turning.

Starts second time.

Doesn't do it all the time and it seems to happen when cold or after a day or so of non use. No other electrical problems other than a stalk related issue a few weeks ago.

Could it be a bad earth or is the starter/solenoid beginning to die?

When you say 1 rev - you mean you think its turning engine over once or twice? and Not enough Punch in it?

2nd time its able to start engine okay?

It'd defo looking as if the Starter Motor is Weak
But a Weak Battery could also be affecting it

The cold is affecting most of these things atm

Ziggy

New starters are pretty cheap but get the battery stress tested and make sure the main earth is properly connected along with the +ve to the starter.