Well, that was worth waiting for, wasn't it? Almost seven long months after Britain voted to leave the EU, the prime minister at last spells it out: we really are taking our destiny into our own hands. No Single Market. No full membership of the customs union. And no more of those huge annual payouts to Brussels. Yes, Brexit truly does mean Brexit.

How the gloomsters hate it. "Woe, woe and thrice woe," cries Lord Mandelson on the BBC's Today programme (of course, I'm paraphrasing him somewhat). "A theft of democracy," blusters the Lib Dem leader Tim Farron. Like all the other Eurotoadies, they seem convinced that poor, feeble Britain can't possibly thrive unless it clings to the Single Market, obeys every last instruction from the European Court and surrenders all control over its own borders.

But is the Single Market really all it's cracked up to be? Let's look at some of the facts the Remainers never care to mention.

First, the EU is the world's slowest-growing economic bloc. In the last 20 years its share of global trade has shrunk markedly. Over the same period, the share of British exports going to the EU has tumbled from more than 60% to around 44%. What's more, we've had a permanent balance of payments deficit with the EU ever since the Single Market was created. At the same time, we have a substantial surplus in trade with the rest of the world – and it's on the increase.

The case for the Single Market is even weaker when you examine the way it discriminates against a British economy so heavily dependent on services such as banking, international finance, insurance and legal expertise. EU rules are regularly and cynically rigged to prevent us utilising these skills properly.

Isn't the Single Market supposed to guarantee freedom of services? Indeed it is. But again and again countries such as France and Germany have conspired to wreck schemes that would have allowed Britain to operate in European financial markets. And so an ambitions Services Directive proposed in 2006, was deliberately neutered, to Britain's great disadvantage. A planned Takeover Directive was wrecked too, in order to frustrate 'Anglo-Saxon predators'.

So is it really worth our while to belong to this flawed and failing system when it costs us £9bn ($11.2bn, €10.4bn) net in financial contributions every year, prevents us from controlling our own borders and erects so many obstacles to our services sector? Clearly not. When Jeremy Corbyn complains that Theresa May 'seems to be wanting to have her cake and eat it' , he simply shows – not for the first time - that he's badly out of touch.

This flawed and failing system costs us £9bn every year, prevents us from controlling our own borders and erects so many obstacles to our services sector

For this was a speech Mrs May simply had to make. She's been under the most intense pressure for months to say exactly what Brexit means. Opposition parties have been claiming – foolishly, as it turns out – that she doesn't have a clue what to do next. At the same time, companies have been complaining that the uncertainty is affecting crucial investment decisions.

Meanwhile some of our European partners have been insisting on the need to 'punish' Britain for daring to assert its independence. French President François Hollande, for example, warned "There must be a threat, there must be a price... otherwise other countries or other parties will want to leave the European Union." And that may yet turn out to be the EU's negotiating position.

Now the prime minister offers a better and more intelligent option: a new relationship of friendship and co-operation with the EU, a free-trading partnership that can benefit both sides, even a willingness to continue participating in some European programmes.

But there's an element of steel in all this, too. She warns that if Europe follows Hollande's dismal advice and tries to penalise us, it would be "an act of catastrophic self-harm". Britain would then have to consider transforming itself into a kind of European Singapore, a low-tax, low-regulation economy that would attract investment from round the world and completely outshine the sclerotic, overtaxed and over-regulated EU.

Well, I don't for a moment suppose it will come to that. Common sense suggests that we'll reach an accommodation with our partners that will satisfy both sides. At the very least, Mrs May has set out the direction of travel. And left all of us, the EU included, in no doubt of her belief that no deal is better than a bad deal.

Michael Toner is a former Fleet Street political editor and co-author of a series of Bluffers' Guides on Europe.