I have a valid UK multiple entry standard visitor visa. But this time I'm actually going through London in transit - flying in, staying overnight in the airport hotel and then going to another country from another airport.
I know there is a special visitor in transit visa for such cases (and based on my nationality I need one), but my question is if I can use my existing standard visitor visa (which technically allows to do a more extensive visit, but not sure if just transit is also fine under it) to cover my transit?
Or would it be enough to say that I want to see London on my way to have my visit classified as tourism (i.e. become consistent with the type of visa I have) rather than transit despite the short period of stay?