Chris Mason: Defiant Boris Johnson leaves office but not the stage

Why on earth did you get rid of me?

Boris Johnson didn't use that sentence, but he might as well have done.

I'm writing this standing at the back of Downing Street, looking down towards the security gates and Whitehall, and the circling pods of the London Eye beyond.

Some of the prime minister's most loyal allies are sharing hugs and souvenir snaps.

As Mr Johnson and his wife Carrie Johnson head to Balmoral, there's time to unpick some of the words he chose to use to mark his departure.

There was a defiance - a claim the rules had been changed. They hadn't.

The simple truth is: no prime minister has ever been able to stay in office without the confidence of their party. And he lost that.

There was an extensive assembly of what he saw as his greatest hits - the coronavirus vaccine programme, Brexit and support for Ukraine among them.

But also reference to a panoply of other policy priorities including better broadband, improved social care, new train lines.

This was less a list of achievements, but projects begun or hoped for but many not yet delivered.

His was a premiership terminated prematurely against Mr Johnson's will, and that frustration, that anger, was buttered with self-deprecation and wit.

And then there were those references to the future: one wrapped in the imagery of space exploration, the other in classicist comparison.

Will Mr Johnson really "splash down invisibly in a remote corner of the Pacific"?

And aren't rockets fired towards the stars the ultimate televisual events, watched by millions and planned meticulously?

Every syllable Mr Johnson utters, out loud or in print, will magnetically allure the cameras, microphones and reporters. Commanding attention has been his greatest skill throughout his career.

He knows that and will revel in it - the student classicist even referencing a Roman dictator who made a comeback.

I'm told his future interventions will focus on the aspects of his time in office of which he's most proud: Ukraine and what he calls "levelling up".

In short, Mr Johnson is leaving office but won't leave the stage.

We'll hear from him again.

But we still await the big speech of the day: when Liz Truss arrives here in Downing Street at teatime as prime minister.