Im probably right in thinking i need a new mechanism.

Basically when i come to unlock my drivers door the key keeps turning clockwise unless i am very gentle with it then it does unlock. Locking anti-clockwise is fine at the moment but i fear the lock will go altogether soon. I don't have remote locking just manual. Any ideas on a fix or where to get a cheap replacement unit welcome, also if i do replace the mech unit will it come with a different key or can i still use my existing key?, thx in advance ;-)

Quick Update for other people with this issue. Just got round to fitting the new door lock barrel I ordered from Skoda to fit existing key £36.84. I was worried about dropping screws inside the door, having to remove the door panel etc. But to my amazement as my mechanic said it was so easy. Just remove the 2 little black plastic caps off the door edge to reveal 2 torx screws, undo these so they are loose but not removed then the whole lock barrel just slides out of the front of the door, replace the barrel and slide it back in, tighten the screws, replace the plastic caps. Job done!!!! Happy to have a trouble free door lock again, thx to all who helped with this, and I hope this helps others ;-)