Remember the sheer relief when Theresa May was catapulted into No 10. The country breathed a great “Phew!”

Thank God it’s not a sociopath, an eye-swivelling “no experts” obsessive or an inexperienced dimwit. We had escaped the terrifying prospect of extreme Brexiteers whose breathtaking Trump-class lies had swung the referendum.

When May was suddenly the last one standing, how solid and capable she seemed in comparison. That ice-cool calm was balm after the hot campaign, where she had kept deep cover. Anyone surviving six years in the Home Office, notorious graveyard of political ambition, must surely be competent? Optimists could seize on her glimmerings of liberalism — good on domestic violence and racist stop-and-search.

Pessimists shuddered at her snooper’s charter, “Go home” vans and pledge to withdraw from the European convention on human rights.

But evidence was thin: in truth, we hardly knew her. Her no-small-talk, reveal-nothing reticence left everyone free to invest in her whatever they chose. Her threshold speech was elegantly expansive with her personal motto, “A country that works for everyone” — not for the fat cats but for families just getting by.

Now the honeymoon is over it’s time to take a wary look at who we are tied to in this shotgun marriage. With no campaign, there was no scrutiny, no cross-questioning and no combative television debates; there was neither a selection nor an election. The wary will have heard her opening progressive pitch with healthy suspicion after David Cameron’s hoodie, husky, let-the-sun-shine-in compassion morphed overnight into a sharp right turn.

Today Cameron scuttles away from politics, tail between his legs with much to be ashamed of. May faces a nation beset by its worst crisis since the war: the Brexit nightmare looms over everything, and the economy is dogged by abysmal productivity, low pay, low skills and a huge trade deficit. She faces an NHS in meltdown due to severe underfunding, a worsening housing crisis and precarious public services. The veneer of civilisation wears thin.

Reviewing her inheritance, May was expected to proceed with characteristic caution — but what if she is not that careful person at all? She is emerging as someone altogether more reckless and less competent. Start with the most pressing question: why did she put three vain and extreme mavericks in charge of Brexit? David Davis announcing at his first Commons appearance that staying in the single market was “improbable” had to be slapped down immediately.

Liam Fox, touting for British trade, calls British business lazy. And Boris Johnson, as foreign secretary, joins a “hard Brexit” ginger group. What do they want? Crazy, dangerous things.

Fox is for quitting the EU customs union, imposing customs checks on all exports, and a Northern Ireland hard border.

Former ministers are just as bad. John Redwood’s “Go now, no deals” panics all exporters and importers. Nigel Lawson’s “Lift all tariffs” would put 10 per cent on selling cars to the EU, while ruining our manufacturers with cheap imports. These uncontrollables seek a radical EU break and potential mayhem, leaving May’s chancellor bleating that a single market must be preserved for the City. Why such chaos so soon, when she should command absolute authority?

The NHS risks haemorrhaging EU staff, while agencies fail to recruit more from Europe, due to Brexit. Last week May called in NHS leaders to order them to stop any hospital mergers or closures that risk causing local protests. But if they can’t make savings, has she understood the vast size of the NHS crisis? As for health prevention, she bent to the will of the food industry over sugar and obesity.

But it’s over grammar schools that she has truly squandered her reputation for caution, competence or moderation. This bombshell dropped out of the blue sky without rhyme or reason, ignoring evidence, plunging schools into yet another bout of turmoil. Her oxymoronic “inclusive grammar schools” may focus-group well — until most parents realise their children will be rudely rejected. The 11-plus brands you for life: after admitting in print that I failed, I still get abuse, telling me that proves I’m too stupid for this job.

The UK has no problem with high standards for its top half of children, who do well on international scales. What drags us down is abject failure with the low achievers. We have cut further education courses, there are few good apprenticeships.

This week’s report by the Institute for Fiscal Studies shows those “who don’t get into grammar schools do worse than they would in a comprehensive system”.

May uses the word “meritocracy” without irony, though it was coined by Michael Young in a dystopian satire. Stop and think: what is merit? Goodness, hard work, community-mindedness? Or just the genetic accident of talent? Inequality is monstrously unfair in itself, and not just because it means birth is almost always social destiny.

If social mobility were May’s genuine intent, she would start not with 11-year-olds, but the best nurseries and children’s centres where life chances can be changed — but these are closing. What a bad omen that she ignores “experts” for a nostalgic better yesterday.

Irrational in the extreme is her multiplying of faith schools — segregation by culture, race, religion and class. Faith schools are strong class segregators, on average taking a third fewer free-school-meals children. Already a quarter of state places in England and Wales are in faith schools, in this least religious country. But she is letting them drop the obligation to keep half their places for others, after Catholic and Jewish leaders refused to create more free schools unless they could keep 100 per cent places for their own. How does this fit with religious de-radicalisation?

None of this looks like a safe pair of hands taking back control in a country beleaguered by uncertainty. May seems set on answering the wrong questions in the wrong way, adding to splits and divisions. Her only piece of good luck is the disappearance of any credible opposition — but she looks well on her way to filling that void with alternative opposition groups within her own party.

— Guardian News & Media Ltd

Polly Toynbee is a columnist for the Guardian. She was formerly BBC social affairs editor, columnist and associate editor of the Independent, co-editor of the Washington Monthly and a reporter and feature writer for the Observer.