Getting married wedding presents?

me and my soon to be missus are soon to be wed, hopefully in september. were trying to keep the whole event low key but the sad fact is as soon as were wed i'll be carrying my missus across the threshold of rented accomadation. the same place we've rented for the last 3 years. anyway we have everything we need but no space to put anything else. is it ok to ask that all guests may/can contribute to a chosen charity rather than give us presents?. as i said low key, we dont give a crap who does or doesnt come. i'd rather see 50 quid go to the NSPCC than be spent on a new blender for us.