We have some mould left on ceilings from when the house was drying out. I don't think we have any issues with damp now but as the painters are coming on Wednesday I was wondering if I need to bleach over the mould or use a mould spray on it and give it a wipe?

Dettol mound and mildew I use, but tbh prob just 50/50 water/bleach is the same thing at a fraction of the price. Spray on, leave for 5 mins, wipe and relax. 

I've used HG mould spray (I think I picked it up in B&Q) with success on a couple of small areas before painting - seems to be no ill effects.

(FWIW the spray is the absolute daddy when it comes to removing well established mould from large areas before giving your house back to the landlord)

+1 on the HG products ! Very good for a lot of stuff.