There is no such thing as permanent victory in politics. History never ends: triumphs are fleeting; majorities can turn into minorities; and orthodoxies are inevitably built on foundations of sand. Communism was supposed to be discredited forever after the collapse of the Berlin Wall; yet many young people in Britain and America now call themselves socialists.

Progress is never guaranteed in politics: there are just ups and downs and swings of the pendulum.

This applies to Brexit too, of course: those who thought that Leave’s victory on June 23 somehow settled the question were deluded. The good news is that it remains likely that we will leave the EU in 2019.

Theresa May is fully committed and will be canny and steely in her negotiations. But the Remainers are staging a fight-back which is beginning to inflict serious damage on the Brexiteer cause.

Every piece of bad news is blamed on Brexit; an endless supply of reports, economic “forecasts” and articles explain how leaving the EU is self-evidently bound to hurt us, slash our GDP, make us the world’s laughing stock and wreck our prosperity. Even Ed Miliband and Peter Mandelson are back.

Remarkably, given that the insurgents were meant to have seized power, the propaganda wars have been one-sided: the Government isn’t really taking part, and the other Brexiteers have vacated the battlefield.

Unless Mrs May decides to change tack, and becomes much more aggressive in defence of the policy that will come to define her, the Brexiteers will have only one option left: reconstitute a version of Vote Leave and relaunch a full-throttled, independent campaign.

One thing is clear: concern is mounting in Eurosceptic circles.

It’s not just the specifics of how we leave the EU that are still up for grabs. Some Remainians still hope that withdrawal can be delayed long enough for it never to happen; others are discussing whether Article 50 could be reversed once it’s invoked.

David Fuller's view

I sympathise with these comments and the sentiments of many friends and colleagues who voted for Brexit.  Wouldn’t it be wonderful to fast forward and be entirely outside of the EU, a sovereign state once again, trading with the global economy and not just the failing EU.   

To happen anytime soon, this requires a declaration of Article 50 in early January, followed by a list of UK terms for trading with EU partners in our mutual interests, which does not impinge on UK sovereignty.  This is not a blink moment for the UK.  It is a final offer, which we should assume will probably not be accepted by Merkel and Hollande, in which case we respectfully withdraw.  I believe this is what Patrick Minford and Roger Bootle advise, and they would be very useful contacts for the Prime Minister. 

EU threats of fines, ongoing commitments and binding agreements extending well into the decade, which have been bandied about, are little more than attempted bullying tactics to prevent any country, heaven forefend, from leaving the dysfunctional EU.  There are no Brexit terms; the UK is creating them as it leaves. 

Would hard Brexit result in turmoil?  Almost certainly for a brief period.  Thereafter, I think the majority of UK citizens and residents from other countries contributing to the UK economy would welcome the new challenge and get on with it in our mutual interests.  The UK government should now be forming its plan of action and recovery, in this event.

The Prime Minister may think a more cautious, exploratory approach could be more effective, not least as dissatisfaction and turmoil within the EU is not only increasing, but could easily lead to the electoral fall of Holland and perhaps also Merkel in 2017.  Perhaps, but that would not necessarily favour the UK.  Moreover, a long drawn-out negotiating process would likely be far worse for the UK - in terms of national morale, unity and capital - than a swift, hard Brexit.

Here is a PDF of Allister Heath's column.