The last time a United States presidential hopeful came to London police had to hold back crowds as the rare sight of a beaming Gordon Brown ushered Barack Obama through the door of No 10.
But that was in 2008. Three years later, Britain has a Conservative Prime Minister and the man whom many have tipped to mount the Republican challenge to Mr Obama in the next election has arrived in London to solicit funds – largely by the back door.
Mitt Romney, the former Massachusetts governor, landed in the UK yesterday afternoon to deliberately little fanfare. He was heading to a fundraising dinner and meetings with only a handful of officials. He will, according to No 10, meet the Prime Minister "if there is time in [Mr Cameron's] diary". At the moment, it appears there will not be any.
Tall, clean-cut and greying at the temples, Mr Romney looks every inch a Republican president. But it is an appearance undermined by a contradictory background that includes his surprisingly liberal record as a governor and his chosen place of worship – The Church of Jesus Christ of Latter-day Saints. In the course of the last three months, he has embarked on an enthusiastic fundraising drive, earning $18.25m (£11.5m) for his campaign coffers.
Last night, it was the turn of London's American expat community to be there for the glad-handing and panhandling at the dinner at Dartmouth House in Mayfair.
Mr Romney and his team were tight-lipped on how many people were at the event and who they were, refusing to reveal even the cost of a ticket.
Mr Romney is to meet Sir Peter Ricketts, the British Government's National Security Adviser, today.