'My friends, you have waited for the punchline of this speech' said Boris Johnson after 11 minutes of what sounded very much like a leadership speech. 'That having consulted colleagues and in view of the circumstances in parliament I have concluded that person cannot be me.'

Theresa May has been slightly ahead of Boris in the surveys of Tory members and voters so far. Now she is the front runner. But it is worth remembering that Gove always receives a rapt reception at party conference and many Conservatives went into mourning when he was moved from the education brief.

Gove has also been the key driver in government of the Conservatives' social justice agenda. His sessions at party conference have often felt rather evangelical, with testimonies from parents whose children go to free schools and reformed trade union leaders. James explains in this week's magazine that the new Tory party is one that is concerned with social justice and reform, and the Justice Secretary is surely the embodiment of that.

This is of course a dramatic end to Boris's Prime Ministerial ambitions. His prospects had yo-yo-d over the past year since becoming an MP. He had a difficult start last summer, struggling to impress his own new intake and political cabinet meetings before warming up a little in the autumn. His performance in the referendum and the result made things look rather easy for Boris, right up until this morning.

But what often struck me in conversations even with Boris's most ardent fans was that they could really only speak of his election-winning abilities rather than his talents as a leader or suitability for running Number 10. Perhaps he will be able to continue as a Conservative mascot, wheeled out in marginal seats to win the party votes, but he will always have a little less excitement around him from now on.