Theresa May has just delivered a remarkable speech – that is, to say, a speech that were it delivered by anyone other than the Prime Minister anywhere other than the steps of Downing Street, it would likely result in the police gently asking them if everything was quite alright.

In response to the leaks about May’s awkward dinner with Jean-Claude Juncker, the Prime Minister has accused officials and politicians in the European Union of seeking to influence the general election on 8 June.

Let’s break it down. As I wrote yesterday, the Juncker leak has to be seen through the prism of the fact it was a leak to a German newspaper, for a German audience. As is often the case with such leaks, Juncker – who either leaked it directly or had it leaked by a subordinate – comes out as rather wittier than you imagine he was in person. It suggested that Downing Street's expectations for Brexit were through the roof and an exit with no deal was likely. It should primarily be seen as preparing the German electorate for the possibility that it will have to pay more into the EU if Britain leaves without a deal.

The row was a double benefit for May. It increased the salience of the Brexit deal and the question of who people want negotiating with the EU27, one which, both Labour and Conservative strategists believe, hurts Labour and helps the Tories. It also gave her the opportunity to gain some goodwill with her European counterparts by not rising to it. David Davis did a good job of that this morning, shrugging it off and saying there would be no “megaphone diplomacy” from the British end.

Unfortunately, that turned out to only be half true. May’s speech was all megaphone and no diplomacy. And if politics is viewed through the crude prism of who wins in June, it was a great speech. It further cast the election as a special one-off event in which people need to lend their votes not to the Conservative Party but to Theresa May. It hinted at the idea – which will become more explicit as the campaign wears on – that there is something about Labour under Corbyn that is not only unfit to govern but actively dangerous.

It would be a silly speech to give if the Conservatives were level in the polls or even trailing Labour. Giving it when the only question is the scale of the Tory victory is reckless. Yes, the polls have been wrong before. But it would require the miss without historical precedent for the benefits of this speech in the election campaign to outweight the costs to Britain thereafter.

The challenge for May is not beating Labour – it’s getting the best Brexit deal after the election. It wouldn’t hurt if she started to take that latter part a little more seriously.