Passenger door sticking - please help

[solihul]

I've noticed that when I first open the passenger door on my car in the mornings it opens about a centimetre and then gets stuck on I can only persume the latch. No matter what I then do the door will not open and I have to close the door completely and them it opens.

This happens the the first time that I open the passngers door everyday and everytime after that it is fine,

Any ideas