I'm planning to travel to the US via London. I'm travelling with an official South African Passport as a government official and allready have a visa for the US.
The flight that I plan involves landing at Heathrow Airport, but the connecting flight to Las Vegas departs from Gatwick Airport. My question is the following: Will I be allowed to enter London in order to travel to Gatwick Airport without a UK visa? If not, what are my options? Any advice will be appreciated!