You must be across the pond from us? Modifying your profile so we have a clue of where you live would help.
Meanwhile. Is the ceiling in good shape but just glossy looking? You know with any paint prep you have to scrape away peeling paint and make repairs?
You need to rough the entire surface up with either sandpaper or a chemical de-glosser. You need your new paint to adhere.
If was not sure what paint was on a surface (but I always knew) I would lay down a nice alkyd primer. I think alkyd primer films the great equalizers. You can paint over them with anything. They now come with water based formulas but I still trust the oil solvent based ones more.
thanks for your reply, have updated my details, its the first time i have decorated this house, and when i removed all the wallpaper from walls and ceilings i discovered it was all gloss painted, i wanted to paint the walls and ceiling, bit not with gloss paint, but not sure what to put on first so the paint will adhere.