The central fact of this Parliament – and perhaps of the entire post-war period – is that Britain has voted for Brexit.  Everything else now lives in its shadow.  The budget deficit, foreign policy, social justice, deals for trade – all must be recast and reordered within the framework of a decision that 52 per cent of the British people voted for and roughly 75 per cent of MPs opposed.  Getting its substance rather than its shadow through the Commons in the next few years will therefore be very hard work.  But happen it must – not only because it is right, but because if it does not the mainstream parties risk a Italian-style revolt against the entire political class.  Labour is already in peril of being eaten by one.  The danger for the Conservatives may be more remote, but it is real.

This is the best place to start when considering the membership stage of the leadership election that lies before us.  Michael Gove is out.  Andrea Leadsom and Theresa May stay in.  The former has less than half the votes of the latter.  And the former has more than half the votes of her MP colleagues.

May has said that “Brexit is Brexit”.  In other words, there is no difference between the two candidates in terms of their aim.  Some doubt that she means it.  They point to the devoted Remainers who have queued up to support her: Ken Clarke, Anna Soubry, Damian Green, and so on.  It may just be that these critics are right; it’s far more likely that they are wrong.  This is not only because May, though as capable of being tricksy as any other politician, is straighter than many of them, but because she will know the consequences of backsliding.  With a majority of only a dozen or so, her Government would fall.

But either way, the plain fact now is that only May the Remainer can deliver Brexit through this Commons and Parliament.  Leadsom cannot effectively do so on a base of 84 votes.  A win for her in the second stage of the contest would be a Jeremy Corbyn victory – in other words, an empty one. She might command the support of party members; but she would already have been rejected by MPs, twice as many of whom would have voted for her opponent.  The British political system is ultimately a Westminster-based one.  Leaders must command the support of those they work with every day.  This matters even more in government than in opposition, because the stakes are so much higher.

Only May now has the capacity, with the backing of MPs and hopefully Party members behind her, to cajole, wheedle, plead, threaten and charm the Remain-backing majority of Tory MPs to back a coherent Brexit plan.  Most of them are already willing to do.  They know a mandate from voters when they see one.  That leaves a hardcore of between perhaps 15 and 50 MPs.  If May would find them difficult to manage, Leadsom would find them impossible.  She has had a rough old ride from the media so far, and her campaign has been rickety at best.  Yesterday’s strange march looked as though it was competing with Nick Boles’s text messages in a race to the campaigning bottom.

Leadsom may well now recover her momentum: many party members will not like seeing her trashed simply because she is a social conservative and practising Christian (though on the latter score, so is her opponent).  But whatever happens during the next few weeks, she will not now have the authority to govern the Conservative Parliamentary Party.  Some Party members will doubtless insist that it is their decision, thank you very much, and that if they want Leadsom, then Tory MPs must put up with it.  It is their right to do so, and one this site unflichingly supports – and campaigns for.  None the less, what one has a right to do is not always what it’s right to do.

Never was this more applicable than now.  The voluntary party will not be making a choice, as it has done for the last four leadership elections, in the comfort of opposition, knowing that the new leader has time to play himself in.  The circumstances are unique.  The Conservative Party has held leadership elections in government before.  But never has it done so with a Prime Minister retiring from office.  His replacement will come to office at a supreme national moment.  This would have been a daunting challenge at the best of times for a candidate who has never been a member of Cabinet.  With less than half the votes of her opponent, it looks impossible for Leadsom to meet.

This is not to say that she should withdraw from the contest.  In 2005, David Davis saw through the membership stage of the leadership contest knowing that he would lose, but thereby honouring the members’ right to have their say.  Leadsom is not quite in that position now.  Our recent survey and a YouGov poll suggested that she is picking up support.  But even if she and her team believe that victory is impossible, we urge them to campaign on for the Party’s and, more importantly, the country’s sake.  If the Remain-backing May is to be the next Party leader, she needs the legitimacy that can only come from winning a full leadership contest fair and square – a point she grasps very well.

She will also, if victorious, be Prime Minister.  This is an awesome responsibility at the best of times.  At these, not the worst of them but certainly the most dramatic, the scale of the challenge is scarcely comprehensible: bigger than that which faced Margaret Thatcher in 1979, almost as great as that which faced Attlee in 1945 – or Churchill six years earlier.  Her Tory critics believe that she simply isn’t up to the task: they portray her as a timid bureaucrat, unwilling to delegate, imprisoned by conventional thinking, politically correct.  This is not ConservativeHome’s experience.  Certainly, we have disagreed with her often – most notably over the European Arrest Warrant.

But we have seen at first-hand her frustration with EU migration, the honourable if cunning way in which she conducted herself during the referendum campaign, her toiling work on police reform, her dogged pursuit of Abu Qatada, her careful but solid approach to counter-extremism, the passion with which she has tackled human trafficking: above all, her willingness to probe a problem from first principles, rather than ask how it can best be spun for the cameras and the prints.  The daughter of a vicar, with a sense of duty etched into her bones, May is a classic public servant.

In the very week in which Chilcot has judged Blair in the court of public opinion, and found him wanting, May has topped the MPs’ ballot in this leadership election.  It is a sign of the times – an indication that the Blair era is finally coming to an end, in a flash of gunpowder and a whiff of sulphur.

For just as Tony Blair was raised in the shadow of Thatcher, so David Cameron and George Osborne were raised in the shadow of Blair.  In terms of style though certainly not of substance, they have indeed been the heirs of Blair: there has been a focus on presentation – a continuum of the man that the Chancellor is reputed to call the Master.  New times are upon us.  Cameron is going, Osborne should do, Boris is gone (for the time being) and now Michael Gove, with his brilliant gifts, is out.  He delivered grown-up government alongside May during the coalition years.  We have reason to hope that we are on the verge of more.

While Labour has yet to trouble the scorers, the Conservatives are about to give Britain its second woman Prime Minister.  Those wicked, reactionary, effing Tories have done it again.  Disraeli, the first Jewish Prime Minister.  Thatcher, the first woman Prime Minister.  Now a choice of two women – May or Leadsom.  The latter’s time may come.  But it is not now.  For the sake of Britain and Brexit, for a manageable Commons and the country’s future – not to mention restoring orderly government as soon as possible – we hope that Party members vote for the former.