In about 1992, I went to an official Cocktail Party in Durbar Court, the very posh atrium area at the Foreign Office.
.... a very agreeable venue. But no red wine on the ground floor IIRC, lest a spillage mar the white marble floor.
But that was in Noo Laybah times, so perhaps it was Elfan Safety. And neither Robin Cook nor his "secretary" looked any better in the flesh.