If you're inbound to Gatwick VFR the last thing you should be given is vectors on to the ILS. Tell ATC you can't do that if they suggest it again!
Why oh why do they over control in such ways?
You should just be told to position for a left or right base join then held on a base until told to position number two to whatever it is you're to follow with a "caution vortex wake, recommended spacing is x miles" thrown in.
You then position yourself on final behind the traffic and, if you're sensible, you fly above the preceeding traffic's glideslope, land long and vacate.
Oh so simple...