Angela Merkel’s visit to London could hardly have been given a bigger billing; a speech to both houses of parliament, lunch with the prime minister and then tea with the Queen. David Cameron clearly had high expectations that Frau Merkel would be open to his agenda for reforming the EU. In part, he’s right – but in a number of key areas, he will be sorely disappointed.

Anyone watching Merkel start her speech in Westminster Hall could have thought that a visiting monarch was in town. The first few minutes of her address, delivered in heavily accented but nonetheless perfect English, flattered her hosts. She talked of when she visited London for the very first time (to attend a science conference and, so we found out, to pop by and listen to the wild and woolly orators at Speakers’ Corner), and the immediate affinity that she had with “die Insel”.

She then moved on to talk about similar common interests in preserving peace, defending the single market and shaping the European economy to deal with (not inconsiderable) future challenges. This was the speech of someone at the top of her game, a stateswoman whose every sentence was crafted to tell a story and to make an impact.

At the peak of her powers she may be – but Superwoman she is not.

Get real

Merkel said tantalisingly little about the detail of what future reform of the EU will look like. We know she doesn’t want (at any cost) to renegotiate existing treaties, but we also know that she is prepared to “develop” them. Quite what that means in concrete terms is anyone’s guess. She clearly wants the UK to be part of the EU’s future, but she also says there are limits to what the EU will do to accommodate it. Quite where the red lines are, is, again, anything but clear.

The optimist inside the Westminster bubble could argue that this is ultimately no bad thing: British politicians need to make their case for EU reform (which is something Merkel appears to support), and they have to convince her that their vision of Europe is in everyone’s interest. This may sound like a perfectly reasonable approach, but it throws up various deeply thorny problems.

For one, the British seem to view Merkel as able to do more or less what she wants. Yet she is governing in coalition with a party, the Social Democrats (SPD), that makes the British Labour Party look positively Eurosceptic. Until Germany’s election of September 2013, the SPD was in opposition, yet it supported every one of Merkel’s initiatives to solve the Euro crisis. The SPD’s willingness to allow (yet more) British opt-outs from what they see as fundamental parts of the EU’s core mission will be close to zero.

Merkel’s domestic problems do not end there. Her own political family, the Christian Democratic Union (CDU), has fundamentally different DNA to the British Conservatives. At its core, it is a collectivist party that strongly believes the state is a force for good, and it is deeply suspicious of the individualist ethos of many on the right of British politics. The deeper you look, the more you realise that the CDU part of Merkel’s coalition is more a traditional social democratic party than a supporter of the liberal versions of free trade that hold sway in the UK and the US. Given this domestic context, Merkel is in no position to strike any deal that will satisfy the sceptics on the British right.

Of course, both Merkel and the CDU also believe that the market is a crucial tool for generating wealth. It is for that reason that Merkel and Cameron both argue that the single market is something to be defended. Yet, and this is the second fundamental difference, their visions of what that ultimately means for Europe could not be more different.

Beyond Berlin

When Merkel extols the EU’s importance in nailing down peace and prosperity post-1945, she speaks for the entire German political class. The EU is not, for them, an optional extra. This is not about interests, even as Germany’s interests certainly are well protected within the EU; it is about values, with the EU project as a moral centre. For Cameron and his party, British membership of the EU is premised on a cost-benefit analysis – and for some of them the costs are now high enough that the UK should jump ship. That sort of thinking is anathema to Germans, as even their own Eurosceptic Alternative for Germany party acknowledges. The AfD wants Germany out of the Euro (with the Euro preferably dying in the process); it doesn’t want Germany out of the EU.

Even if Merkel were to overtly support Cameron’s reformist agenda, she would still have to persuade non-German Europeans to join her. And no matter what she may think of the UK’s still rather fluffy agenda, Merkel is not going to do all of Cameron’s work for him. It is interesting to note that while she was offered the full red-carpet treatment on her British sojourn, François Hollande got little more than lunch in a gastropub – even though the French, not the Germans, may be Cameron’s biggest hurdle to striking a revised deal for the UK.

The final problem, which should worry Cameron’s ever-dwindling roster of Europhiles most of all, is the swelling cohort of MPs for whom Angela Merkel’s speech was always going to be meaningless. As far as they’re concerned, there is no bargain to be struck. They are not interested in a “new deal”, or in concessions flung at them as if they were animals at feeding time in a zoo. They want out, and they want out no matter what.

Placating these people, as the prime minister is probably well aware, is impossible. The challenge is to stop them gaining enough momentum to short-circuit Cameron and to ultimately drive Britain out. And while he was nowhere to be seen, Nigel Farage will no doubt have been following events in Westminster Hall on Thursday afternoon very closely indeed.