No choice I'm afraid - the others have reported correctly.
ALL Initial Class One Medicals MUST be taken at the CAA Aeromedical Centre at Aviation House, Gatwick, RH6 0YR.
There you will part with large amounts of your hard earned cash but in return you will be presented with your Class 1 Medical Certificate there and then, on the spot, provided nothing untoward shows up which you weren't aware of.
Subsequent renewal medicals can be done with any Class 1 Aeromedical Examiner, and there are loads of them all over the country.
HTH
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