As a Conservative, I’m apprehensive.  Boris’s declaration for Leave is indeed a Heseltine moment for the Tory Party.  As a journalist, I’m no less surprised than all the others, since it is hard to understand why he is suddenly taking an epic political risk after years of playing it cautious.   But as a Brexiteer, I’m delighted.  Polls suggest that the Mayor of London is the only senior Conservative other than David Cameron who can move voters much either way.  And since country must come before Party – that’s why we’re a pro-Brexit site, after all – perhaps all that’s best said this afternoon is: Boris, welcome to the fight.

All is not quite working out in the Conservative Party as Downing Street intended.  The master plan was for Michael Gove’s loyalty to Cameron to trump his convictions, Priti Patel to be daunted by the prospect of dashing her career prospects, and for Boris to do what he was expected to do.  That would leave a shrivelled Eurosceptic rump, led by Iain Duncan Smith, of 50 or so backbenchers in total.

Instead, Gove put his principles first, Patel stuck to her guns, and Boris has made a leap of faith, or ambition, or conviction, or exasperation – or any mix of four.  Of those with a track record of strong Euroscepticism, only Sajid Javid has gone with the script, explaining in the Mail on Sunday that in his view Britain should never have joined the EU but shouldn’t leave now.  That is not an easy circle to square.  Meanwhile, Guido Fawkes calculates that more Tory MPs are for Brexit than against, with numbers not far off the 150 mark.  That looks on the high side to us – Mark Wallace set out our own approach here – but a minimum of a third or so of Tory MPs seem set to back Leave.

To Gove’s brains, Patel’s fresh appeal, and Boris’s razzamatazz can be added Duncan Smith’s experience and endurance, Chris Grayling’s courage (since he forced the Prime Minister’s hand on Ministerial freedom of action), John Whittingdale’s Thatcherite credentials and Theresa Villiers’s integrity.  Read her ConHome piece of earlier today for its clear case for democratic self-government.

There are men and women of equal brains and principle on the other side of the argument – Ken Clarke, Ruth Davidson, Damian Green, Nick Herbert, and many more.  They might reasonably have been expecting to face fewer senior Ministers on the other side of the argument.  But the Cabinet Brexiteers will be joined by others.  The Fresh Start Group meets tomorrow evening, and Andrea Leadsom and Dominic Raab, two political heavyweights, will be among them.  Mark Francois was a hard-toiling Shadow Europe Minister in opposition and he too is out for Leave.  Let’s hope that the debate is as constructive as the minds are fine.