Meghan Markle and Prince Harry secretly invited London Mayor Sadiq Khan to their Montecito mansion during his recent US trip.
The couple made the invitation after being unable to attend a party hosted by Mr Khan last week in Los Angeles.
But the mayor was unable to accept their offer for logistical reasons, with their home over an hour's drive from his base, according to the Evening Standard.
London Mayor Sadiq Khan
Stefan Rousseau
Meghan Markle and Prince Harry
Caitlin Ochs
Mr Khan flew to New York, before making his way to San Francisco, Silicon Valley and Los Angeles in a bid to boost London’s tourism industry.
Before the trip, Mr Khan said he also hoped to use it to attract investment to the capital.
But he was slammed after saying that an “honest, open” conversation was needed about UK cannabis laws.
He met with LA mayor Eric Garcetti, and visited a cannabis dispensary and farm in the city to see what lessons could be learned in the UK in responding to the challenges of drugs.
Speaking at the Traditional cannabis dispensary and cultivation centre in downtown LA, Mr Khan said: “We need to have an honest, open conversation about the evidence in relation to the history of cannabis and our laws in the UK and our experience of the health consequences in relation to crime and the community.
“The best way to do that will be with the drugs commission we’ve now set up.
“You can hear from the experts, that’s one thing, but seeing it for yourself … hearing from those who cultivate and grow this plant has been fascinating.”
Meghan and Harry are set to travel to the UK for the Queen’s Platinum Jubilee celebrations later this year.
The pair, who will not appear on the royal balcony after stepping down as senior royals, will also bring their children Archie and Lilibet with them.
