Ingnition key in fault

2001 2.5 DT

When I turn the engine off and remove key the Ignition Key In fault comes up when I close the door so won't lock on the remote. Locks on the key no problem and open's up on the remote and starts ok.
Only just happened this morning and had no previous problem so a bit bemused with advice required.

Cheers.

A good squirt of WD40 into the key hole and a damn good wiggle should fix it.its just a sticky switch.