Multipla old style, diesel is really stiff when trying to get into gears when its stood overnight - it grinds and sounds awful and is hard to get into gear - but after a short journey its much better after its warmed up. Any ideas anyone? cheers.

Multipla stiff gears when cold

Grinding gears usually points to the clutch not fully disengaging, is the 'biting point' very close to the floor (i.e. full travel on the pedal)?

Try selecting the gears with the Engine off, to rule out sticky/stiff gearchange cables (although that normally gets worse when everything's warmed up).

Is it the same through all the gear-changes, up and down the box?

Try some clutchless up-changes (2nd-3rd, 3rd-4th, 4th-5th) to isolate the clutch as the culprit.
Just do the gearchange as you normally would, lift-off the throttle in the same way, just don't touch the clutch pedal.

Try lubricating the clutch release pivot arm on the top of the bell housing. Don't overdo it as oil will get in to the clutch housing though. Lubricate lightly and keep working the pedal for a bit and you may find that things improve.

I had terrible graunches and stiffnesses until I did this. I then kept the pivot arm regularly lubricated and my clutch went on for 110,000 miles.