Philip Johnston:

Theresa May is remarkable for her resilience and even difficulties over Brexit are unlikely to sink her

Not since the Queen of Sheba descended on Jerusalem with a retinue of eunuchs and camels bearing gifts for Solomon has an arrival been more anticipated. Boris Johnson swept up the M40 from his Oxfordshire fastness and into Birmingham on the third day of the Conservative conference to claim his rightful place as the party’s heir apparent.

Yet while his fringe event was packed out, unlike the main conference hall which was often half empty, there is a distinct sense that Boris’s time might have passed. Ironically, this is both the best and worst moment for his leadership ambitions.

A Prime Minister assailed by Brexit woes and seemingly out of touch with what her party wants from the EU negotiations would seem to offer Boris, in the buzz word of the week, an opportunity. On the other hand, the Tories are good at throwing a protective arm around their leaders during the party conference, even if they always hold a dagger in the other hand ready to despatch them when necessary.

I remember well the 1990 Tory gathering in Bournemouth, where Mrs Thatcher, then in her Gloriana phase, was cheered to the rafters just a few weeks before her MPS chucked her out of office, or more accurately, her Cabinet did. She, let us remember, had won three elections, had a Commons majority of 100, had actually defeated her opponent Michael Heseltine in a leadership contest, if not by enough under party rules, had played a key role in the fall of the Berlin Wall – and even she could not survive.

Theresa May, by contrast, squandered her majority in the general election, has lost half her Cabinet for one reason or another over the last two years, is accused of backtracking on her Brexit promises, was humiliated by EU leaders in Salzburg; and yet, remarkably, she is still there and shows no sign of going or of being forced out. One joke doing the rounds is that, when the nuclear Armageddon comes, all that will be left on earth will be the cockroaches and Mrs May, such is her resilience.

For now, in the great Brexit boxset binge, the party has hit the pause button and will tune in later to see the gory denouement. Those who expected the conference to be a moment of grave danger for Mrs May don’t understand the nature of the event.

When she addresses the conference today, Mrs May will be greeted with the deference and loyalty that befits her status as leader and Prime Minister. Moreover, many party members and the general public admire the way she is getting on with the job and sympathise with her predicament, not least when it looks like she is being unfairly traduced.

And let’s face it, her speech today cannot be worse than last year when she was interrupted by a prankster, lost her voice and the letters fell off the backdrop in what felt like a metaphor for a doomed premiership.

The blows she has endured since then would have flattened Anthony Joshua; and yet I can only report from seeing her here in Birmingham that she looks in remarkably fine fettle, both determined and optimistic that she will get through in the end. For all the hoo-ha over the type of post-brexit trading arrangements the UK is to have with the EU, most ministers and senior Tories I have spoken to think so, too.

Boris called her plan a “cheat”, which is a pretty serious charge, but he is finding it hard to make it stick among the people who will really matter, the MPS. One veteran Brexiteer put the chances of Mrs May landing a deal and getting it through Parliament at 90 per cent. While an argument may rage now over Chequers minus or Canada plus or Norway squared, once a deal has been reached (and there is too much at stake on all sides for there not to be one), the dynamics will change.

By then – we are talking of the end of November – there will be just a few months to Brexit Day and the choice will be stark. The only options on offer will be what is on the table or crashing out with all the dislocation and panic that would involve. The Labour Party believes that, if it can defeat the Government, an election will follow, they will win and negotiate a different agreement. But time is now so short this seems fanciful.

Labour would presumably seek an extension of Article 50 but this brings its own practical problems, not least what we do about the EU parliament elections in May if we are still in the bloc at that time. There are, apparently, contingency plans allowing British MPS to be co-opted to Strasbourg in the meantime, but you can see how messy it would be.

Defeating the Government would require Tory rebellions, assuming the DUP stays on board; but how many MPS, however disenchanted with the agreement, would risk Parliament falling into a procedural black hole where no one knows what forces will be in play?

In such circumstances, a key figure would be John Bercow since it will fall to him to decide which motions are in order. If the Opposition sought a vote to change the date of Brexit, for instance, could the Speaker allow that when it is already set in statute? A constitutional stand-off between the legislature and the executive never ends well as history shows.

The Conservatives had intended this week to be about life after Brexit but until the deed is done it is hard to move on. Mrs May will do her best to do so later today, focusing in particular on housing and quality of life – reprising, indeed, some of the themes Boris set out in his speech, which was deliberately pitched far beyond Brexit.

He is at his best purveying his infectious optimism and rousing oratory. He is the personification of what politics is supposed to be about – persuasion, enthusiasm, vision – even if some question his application and attention to detail.

He is a man the country might turn to in a crisis to lift the spirits and articulate a sense of patriotic defiance. But even if the next few weeks promise to be among the most turbulent in recent British history, the feeling here in Birmingham is that such an existential moment will be averted. If it is, and she gets Brexit over the line, Mrs May may still be at the helm when the Tories gather again a year from now.