James Constantinou, founder of Prestige Pawnbrokers of Channel 4’s Posh Pawn, said: “Boris Johnson’s traditional style is complemented by Carrie Symond’s love of vintage fashion.
“There is something utterly charming and romantic about buying antique jewellery and antique rings for engagement or eternity rings.”
It is unclear if Boris Johnson will join his wife and attend the event tonight.
Elena Bunbury, chairwoman of the LGBT+ Conservatives, said: “Carrie has always been a good sport to LGBT+ Conservatives.