AT the very moment Theresa May was outside Number 10 bringing her remarks to a close, an email pinged into my in-box. “Book your getaway before it’s too late!” it trilled.

Well, it was too late, for we are all on Theresa Time now.

According to Theresa Time, now is not the moment for Scotland to have a second independence referendum. But as for announcing a snap General Election that the PM had repeatedly promised voters she would not call, why, there is not a moment to lose. Theresa Time: you know it makes sense, to Theresa most of all.

Even by the standards of Westminster, the world capital of brass necks, yesterday’s announcement will take some beating. No longer the heir to the Iron Lady, Mrs May has been revealed as the Stretch Armstrong of British politics, able to go to any lengths, in any direction, to get what she wants. What she wants, according to her statement, is to make a success of Brexit and Westminster is standing in her way. Not the country, note, but Westminster. The Prime Minister has eyed the benches opposite, those ranks of Labour, SNP , Liberal Democrat MPs and others, and fears trouble ahead as she goes about the delicate business of negotiating Brexit. Further, she has looked through Central Lobby to the unelected Lords, and spied more turbulence to come, more “political game-playing”, as she put it.

In other words, it is all the opposition’s fault that Mrs May has to bring about uncertainty and instability now in order to avoid uncertainty and instability later. Priceless. And this from a Prime Minister given to delivering stern lectures about politics not being a game. I think we can now safely put those lectures out with the Christmas tree and the broken microwave as items to be taken to the municipal dump.

Far from not treating politics as a game, Mrs May has just rolled the biggest pair of dice a Prime Minister has at their command. But why has a premier who campaigned for the leadership of her party as a safe pair of hands, the sensible candidate, the continuity politician, acted in a way that seems so contrary to her background and personality? Everything we know about Mrs May suggests she would have stuck with the safe option of staying put until 2020, when the scheduled election would have been held. She was, after all, the UK’s longest-serving Home Secretary of the modern era, a human barnacle on the ship of state. True, she did not have a personal mandate as Prime Minister, but she had the EU referendum vote. Her majority is slender, but not dangerously thin.

As for fearing the capacity of the benches opposite to cause havoc, Labour under Jeremy Corbyn is about as terrifying as a sock puppet; the SNP is present in significant numbers but those numbers are static; and the LibDems remain a busted flush. Far from being a threat to a successful Brexit deal, the troublesome benches opposite could even have been a card to play in negotiations with Brussels.

All of which suggests that the opposition the Prime Minister is truly worried about is not the MPs across the aisle but the ones behind her back. We can split this Tory opposition into two camps, though they are overlapping. There are the naked opportunists who look at the opinion polls and see a 2017 election as a now-or-never way of safeguarding their earnings for a little longer in the event of Brexit going awry and the public turning on the Tories. Never underestimate the survival instinct and towering self-interest of the lesser-spotted Tory backbencher.

Then there is the other opposition within Mrs May’s ranks, the potentially deadlier enemy within. These are currently her friends. They smile at her. They have been smiling a lot since the result of the EU referendum was announced. For these are the grinning Brexiters, never happier than when contemplating the EU-free future ahead of them.

But within the gut of a grinning Brexiter there lurks a doubt, a small yet growing one. And with every week that passes it gnaws a little more. What is this doubt? It is that Mrs May is not really one of them. Even though she spent the referendum campaign largely MIA, only coming out to back Remain when absolutely forced to do so, the Brexiters have their doubts about Theresa. That she may not be as sound as the pound on Brexit, that she could be prepared to concede too much to the hated “Brussels” when they believe the UK should give nothing at all. It is this lot the PM fears. Not a paper tiger Labour Party or a static SNP, but members of her own party, a party that has regicide in its DNA, that has tasted blood before and would not hesitate to shed it again if it deemed it necessary.

Now, there is a part of any observer of politics who will not blame Mrs May for taken advantage of circumstances to strengthen her own position. Better off railing at the tide for coming in than criticising a politician for acting in self-interest. In that sense, what Mrs May did yesterday was to stage a very British, terribly civilised, awfully Middle England, coup.

But how much will it profit her to have done so? As Professor John Curtice of Strathclyde University said yesterday, winning big majorities is not as easy as it used to be. With not much chance of change in Scotland and Northern Ireland, increasing the Tory majority means taking seats from Labour in England. The polls suggest this is possible, but in reality the size of the Labour majorities suggest it will be very difficult. There is always the chance, moreover, that voters will use the election as a way of punishing the MPs they elected in 2015 who subsequently turned out to be Remainers/Leavers: delete where applicable.

What Mrs May needs, then, is the kind of momentum behind her that Margaret Thatcher had in 1983 and Tony Blair in 1997. Yet she enters this election, an election of her own making as surely as the EU referendum was David Cameron’s work, with little of the Thatcher-Blair charisma, and even less claim, given her previous opposition to a snap General Election, to the voters’ trust. If she is rewarded with a bigger majority I do not think for a moment that her problems with the real opposition, those grinning Brexiters, will be over. If that turns out to be the case, her very British coup will have been for naught and deservedly so.