After her first 100 days in power, I’ve rated Theresa May on each of her successes and failures

Unshowy as she is, it is a little odd, you might think, to mark Theresa May’s first 100 days in power. The concept, after all, is an American import, an eye-catching phrase invented by Franklin Roosevelt to reinforce the image of a dynamic new regime taking control in the depths of the Great Recession. He was right to do so – but ever since these heroic days, the notion has been hijacked by politicians in various corners of the world with less claim to it.

May has been careful not to do so. Still, it’s a good moment to assess our headteacher-like premier’s early days, and award some marks for effort, presentation and achievement in her first semester.

Since the referendum that shook the political world in June, the May premiership’s founding, central and defining project – Brexit – can best be summed up as making the best of a bad job. It’s endowed May with a catchphrase: “Brexit Means Brexit”. Even though that is, paradoxically, meaningless, like all the best catchphrases it works well as a substitute for a policy or plan, of which there is none.

Personally and politically, she has made the transition from reluctant Remainer to committed Leaver, but beyond that, and the commitment to invoke Article 50 by the end of March, there is not much else to speak of. The three “Brexiteers” she appointed, the Cerberus of Boris Johnson, Liam Fox and David Davis, can hardly be blamed for not having concluded new global trade deals, but we also know that the May Cabinet is split about the terms of exit and unwilling to admit it, hiding behind the line that they won't “give a running commentary”.

The Treasury remains deeply unhappy about the prospect, and hasn't convincingly stepped away from the “Project Fear” forecasts it issued under George Osborne, no matter what his successor as chancellor, Philip Hammond, says now about having “the wrong assumptions” in the old figures. Outwardly loyal, but careful in his choice of words, Hammond is quickly emerging as the leader of the opposition to “hard Brexit” at the top of the Government. His catchphrase: "No-one voted to become poorer". Already the briefings against him have started by the hard-line Eurosceptics.

Thus did the referendum that changed everything change nothing, with the Conservatives as deeply divided on Europe as ever. One hundred days have not been enough to sort that out. Theresa May might yet turn out to be another Tory leader, after Thatcher, Major and Cameron, to see their premiership marred and ultimately broken by the question of Europe. The next 1,000 days, taking us past Brexit, will be the timeframe for that.

Effort: 8 out of 10

Presentation: 7 out of 10

Achievement: 1 out of 10

May’s innate caution is a feature we have become accustomed to, but that doesn’t mean she can’t take a decision or doesn’t do her homework (in contrast to her overly laidback predecessor). She called in the enormously expensive Hinkley Point project and is taking her time over Heathrow, with some suggestions of yet more fudging – but a move on that cannot be long delayed.

On the other hand, plans for ambitious infrastructure spending – for example on roads and rail – will be that much more difficult to fund as investors demand higher interest on UK Government bonds (which were downgraded by credit agencies soon after Brexit). The uncomfortable truth is that these investments should have begun some years ago.

Effort: 6 out of 10

Presentation: 6 out of 10

Achievement: 5 out of 10

May’s most adventurous initiative, grammar schools, was a bit more of a drama than the usual Theresa style of government because it was accidentally revealed by a sharp-eyed cameraman who spotted some official paperwork going into No 10. She won't win all the arguments on this, and the parliamentary battles will be attritional, but her line that we already have selective schools based on house prices does resonate with the public, and that will be important as she battles with the House of Lords, backbench dissidents and the teaching profession.

Effort: 8 out of 10

Presentation: 8 out of 10

Achievement: 7 out of 10

Linked to Brexit, Theresa May’s greatest challenge will be dealing with a slowing economy, rising inflation and stagnant living standards. The depreciation of the pound – the currency now being the effective opposition to Brexit – will inevitably push prices higher and make it more difficult for the Bank of England to keep supporting the economy with ultra-low interest rates, which we've had for seven years now. Besides, the US Fed seems ready to push global rates higher by the end of the year.

A slumping pound, rising commodity prices and world interest rates on top of Brexit mean May faces a very difficult challenge. We will see in the Autumn Statement later in November what strategy she proposes to deal with that.

Effort: 7 out of 10

Presentation: 6 out of 10

Achievement: 5 out of 10

“A country that works for everyone”, a better deal for ethnic minorities, and social justice more widely are unusual themes for a Conservative leader. May’s rhetoric since she arrived in office has been unrelentingly liberal: she has rejected “the libertarian right”, praised Clement Attlee and embraced “the good Government can do”. So far, though, there is little to show beyond this admittedly smart move to occupy the centre ground. Lack of funds will constrain her drive for equality, and she risks raising expectations far too high.

In the meantime, her handling of the inquiry into historical child abuse as Home Secretary continues to trouble her and is the nearest we've seen to her starting to look a touch flaky.

Effort: 7 out of 10

Presentation: 9 out of 10

Achievement 4 out of 10

Entirely unexpectedly, the Government’s firm line and some loss of public support delivered Theresa May and Jeremy Hunt a surprising victory in the junior doctors’ dispute. Still, as winter draws in, further hospital crises may not be far away. May has turned down a request for NHS funding from the chief executive of the health service, which she may live to regret.

Effort: 8 out of 10

Presentation: 6 out of 10

Achievement: 6 out of 10

Will Theresa May be the last prime minister of the United Kingdom as we have known it? Again, Brexit-related, this is the most fundamental issue of all, but the unity of the state hasn’t been so unsure since Ireland, or most of it, split away almost a century ago.

Northern Ireland’s status and independence for Scotland are problems the country doesn’t need, but May hasn't shown enormous energy in this direction, and risks being badly outmanoeuvred by the SNP and Sinn Fein. An unusual case of complacency on her part.

Effort: 1 out of 10

Presentation: 1 out of 10

Achievement: 1 out of 10

Here is an issue that tells us a good deal about a politician's moral compass. Take, for example, Angela Merkel’s response in Germany, an open and humanitarian initiative that showed courage and leadership. As Home Secretary and now as premier, Theresa May and her colleagues cannot be said to have acted with anything like the same urgency and generosity.

Effort: 1 out of 10

Presentation: 1 out of 10

Achievement: 1 out of 10

It’s worth mentioning that a PM's first 100 days can be an unreliable guide sometimes. John Major, whose reputation is still awaiting rehabilitation, was the most popular PM in history in his early days, only to be one of the least rated inside a couple of years.

Gordon Brown’s rave early reviews were soon replaced by an unforgiving media highlighting every misstep and clanger right through to the day he lost the 2010 election. Only Tony Blair stayed in “honeymoon” status for very long – about six years in his case. If May wants to emulate him, she must try harder.