Just bought an electric fire - is it cheaper than running a gas fire?

Hi, I've just bought one of those "modern" black gl wall mounted electric fires. It is a compromise with my husband and we thought if we went for this one, it would look very nice and as it sits on the wall it does away with the need for the whole fireplace surround/mantlepiece. You can run it just on the flame effect for as cheap as a lamp but I wondered if you had it on for heat too, would it be more expensive to run than a gas fire?