It is amazing how many people think this, I had to teach the controllers at one of Algeria's largest airports that requesting a visual approach at night does not mean that I am VFR which was prohibited at night. It did not work and we still had to proceed overhead then track a radial outbound to a DME distance then do a turn back inbound. A visual approach is NOT canceling IFR.
I am surprised that someone who claims to fly into Gatwick does not know the difference between VFR and a visual approach.