London Downing Street

Mr Obama, who served in the White House from 2009 to 2017, smiled and waved at members of the press before he entered No 10 shortly after 3pm.

The Privileges Committee is examining whether the Prime Minister committed a contempt of Parliament by misleading MPs over the partygate scandal.

Both the 211 and 148 pick up passengers in Parliament Square, identical to the numbers who backed the Prime Minister and tried to oust him.