It was Saturday morning. I was standing on the steps of St-Martin-in-the-Fields. I was an Usher at my friend’s wedding and I was on the look out for the bridal limo. It was still fairly quiet by Trafalgar Square standards. There was a stage being set up for some sort of event or other. On the steps of St Martin’s, instead of 60 odd tourists sitting, photographing, eating etc. it was just me and one dreadlocked bohemian.

St-Martin-in-the-Fields from Trafalgar Square with the National Portrait Gallery to the left.
David Cameron, his wife and two children approached from the Strand direction (to the south of St Martin’s). They were dressed normally and unaccompanied. I was momentarily stunned but composed myself to seize the opportunity:
“Good morning Mr Prime Minister”
he raised his hand and waved
“Good morning”
and they walked on. Dreadlocked bohemian suddenly wakes up, looks at the back of the Camerons walking away and then at me in disbelief.
“Yes” I say.
“That was the Prime Minister.”
No doubt, at the very moment that I greeted the Prime Minister, a plain clothed police man had my head in his cross hairs.