And this is why I don't do DIY- I attempted to take off the grill to get to the latch however the clips at the top of the grill appeared stuck so I put a screwdriver behind one of them and it snapped... Anyway I did manage to get the other one off. Just cleaned the latch and used WD40 which has done the job for the now.
Thanks for all the help folks, I just wish I was better at the execution!