I have been to No 11 Downing Street before, but today I was invited to a lunchtime reception promoting the referendums for city mayors in my capacity as chair of the Warwick Commission on Elected Mayors.
Michael Heseltine introduced the speakers and joked, 'I hope it will not be misunderstood when I say how pleased I am to welcome you to 10 Downing Street.'
Dave Cameron put the case for elected mayors in terms of greater accountability (being directly elected rather than indirectly elected as leaders of a council); promoting economic growth; and as a platform for developing national political talent. He also noted that the Mayor of Mogadishu in Somalia was called Mayor Tarzan.
Boris Johnson was almost a cabaret turn, albeit one with perfect timing and some good lines. He said that he would 'like to thank Dave for letting me into No.10'.
Closing the proceedings, Michael Heseltine said that whatever else Boris achieved, he would also be remembered as the man who succeeded him as MP for Henley.
The famous photos of prime ministers on the stairs look a little squashed up, but no doubt they can be arranged one day to make more room.