Can the lighter socket in front of the gear stick be switched from 'always on' to switch on via the ignition? If so is it a simple job?

Unfortunately not. If you need ignition switched, you need to run a wire from a fuse tap.

OK many thanks

As above, you either need to use a fuse tap or a caravan split relay

There is actually a very easy way, i did mine just after christmas so both front and back seat are now on ignition.

 

A row or two below the normal 12v socket fuse has a switched 12v bus bar.  Pick a location with no fuse, make up 2 fly leads with male spade connectors on each end.  Then using a separate inline fuse holder connect the ignition switched feed to the 12v socket fuse location.  Obviously just remove the normal fuse and reuse that in the inline fuse holder.

 

inline fuse holder

 

Picture i found showing the method, no idea what this was done for though and what those fuse locations are for but should help understand it:

 

Smighall, thanks for that I may give it a try.

Just use a multimeter to check everything first to ensure you're connecting into the right places.