Brexit regrets? I’ve had a few. And you’d be mad not to. Allow me to mention them, especially now Theresa May has told us that “there can be no turning back” on the road out of the EU. One personal regret is alienating people who I know, who are right to take the Brexit thing very seriously indeed. The Brexit thing has divided communities, friends and families – and the reverberations in Scotland and Northern Ireland will be even more vicious.

“It’s all your fault.” That’s what friends tell me, some angrily, because they know I voted for Brexit last June. The peer pressure is starting to tell on me. So is the course of events, and the Prime Ministers’ apparently hardline willingness to accept “no deal”. Boris Johnson also said it would be “perfectly OK” to fall back on WTO rules. Well, I didn’t vote Leave last June to end up with a “no deal” deal, and I think that “no deal” is worse than a “bad deal” because it is the worst possible deal imaginable. The Prime Minister, in her momentous letter, repeated that possibility, this time trying to link it with security co-operation. So we now have the prospect of no trade agreement with Europe and no security co-operation either, by way of retaliation: again, not something a lot of us ever voted for.

It’s just not sane, the Prime Minister ruling out any change in direction in the national interest if that is where we end up. If she really wants to do that then she needs to have another referendum to win the full-hearted consent of the British people on the actual terms of exit when they are settled.

'No turning back' as Theresa May triggers Article 50

So if that is where we end up, then I would vote against it, because the immediate costs to the economy – and national security – would be too severe, even for eventual rewards from global trading and investment. And, therefore, I do demand a vote on the deal, whatever it is, that David Davis, Boris Johnson and Liam Fox bring back from Brussels. The fact is that Article 50 is reversible if all concerned wish to do so, because it is a political and not a legal matter. The EU doesn’t want Britain to leave, and Britain is in two minds about it still – seriously split with no “clear decision” last June.

We the people have a right, and Parliament does too, to see and have final approval on the eventual terms of Brexit. If we do not like them then we should have the option of staying in, as well as seeking changes. It may even be that the EU, having been through this process, will deliver the economic reforms that so many of its people’s desire (and not just the British). In particular the EU may finally decide that free movement of people is something that no longer commands popular assent, and that the single currency is doing more harm than good to some of the weaker economies. Either way, the “mandate” from last June was not for Brexit at any cost.

If I am betraying genuine doubts I don’t mind. Like many, on both sides, I must say it was a marginal decision, my opting for Leave – I could recognise strong arguments for both options. I wasn’t doing it in some sort of nationalistic spasm. I didn’t put controlling immigration or “sovereignty” above all else. I didn’t believe many of the arguments put forward by the Leave or the Remain camps, as it happens.

On balance I decided that the economic arguments for exit in the long run outweighed those against in the short to medium run. I may be the only person in the country who voted for Leave because they wanted more immigration into the UK. I admit that, looking around at some of my fellow-travellers, I may have been a little naïve in that respect. I also didn’t vote for “English independence”, another unintended consequence. What happens in Scotland, Wales and Northern Ireland is up to the people there. But again if I know now that the consequences will be the likely break-up of the UK, then I can factor that into my decision about staying or leaving the EU. In other words there should be a second referendum, however you want to style it, and Article 50 cannot be called irrevocable for that reason.

How Brexit affected Britain's favourite foods from Weetabix to Marmite Show all 8 1 /8 How Brexit affected Britain's favourite foods from Weetabix to Marmite How Brexit affected Britain's favourite foods from Weetabix to Marmite Weetabix Chief executive of Weetabix Giles Turrell has warned that the price of one of the nation’s favourite breakfast are likely to go up this year by low-single digits in percentage terms. Reuters How Brexit affected Britain's favourite foods from Weetabix to Marmite Nescafé The cost of a 100g jar of Nescafé Original at Sainsbury’s has gone up 40p from £2.75 to £3.15 – a 14 per cent rise—since the Brexit vote. PA How Brexit affected Britain's favourite foods from Weetabix to Marmite Freddo When contacted by The Independent this month, a Mondelez spokesperson declined to discuss specific brands but confirmed that there would be "selective" price increases across its range despite the American multi-national confectionery giant reporting profits of $548m (£450m) in its last three-month financial period. Mondelez, which bought Cadbury in 2010, said rising commodity costs combined with the slump in the value of the pound had made its products more expensive to make. Cadbury How Brexit affected Britain's favourite foods from Weetabix to Marmite Mr Kipling cakes Premier Foods, the maker of Mr Kipling and Bisto gravy, said that it was considering price rises on a case-by-case basis Reuters How Brexit affected Britain's favourite foods from Weetabix to Marmite Walkers Crisps Walkers, owned by US giant PepsiCo, said "the weakened value of the pound" is affecting the import cost of some of its materials. A Walkers spokesman told the Press Association that a 32g standard bag was set to increase from 50p to 55p, and the larger grab bag from 75p to 80p. Getty How Brexit affected Britain's favourite foods from Weetabix to Marmite Marmite Tesco removed Marmite and other Unilever household brand from its website last October, after the manufacturer tried to raise its prices by about 10 per cent owing to sterling’s slump. Tesco and Unilever resolved their argument, but the price of Marmite has increased in UK supermarkets with the grocer reporting a 250g jar of Marmite will now cost Morrisons’ customers £2.64 - an increase of 12.5 per cent. Rex How Brexit affected Britain's favourite foods from Weetabix to Marmite Toblerone Toblerone came under fire in November after it increased the space between the distinctive triangles of its bars. Mondelez International, the company which makes the product, said the change was made due to price rises in recent months. Pixabay How Brexit affected Britain's favourite foods from Weetabix to Marmite Maltesers Maltesers, billed as the “lighter way to enjoy chocolate”, have also shrunk in size. Mars, which owns the brand, has reduced its pouch weight by 15 per cent. Mars said rising costs mean it had to make the unenviable decision between increasing its prices or reducing the weight of its Malteser packs. iStockphoto

So I am under no illusion about the prospects for important industries and jobs, especially in the car industry, in the City and in aerospace, among others. I have little doubt that all of those sectors will suffer, and we will undergo higher unemployment in many regions as a result. I sometimes have nightmares about plausible-sounding news reports for the near-future such as these:

“Nissan UK today announced that it would progressively switch investment form its Sunderland plant to a new facility in Romania. Manufacture of the new generation of Qashqai and related models will be the first to transfer, followed by the electric car unit. A spokesperson for Nissan UK said that the company remained committed to retaining a design studio, employing ‘up to 30’ staff, but that the economics of Brexit, including much more complex arrangements around component supply have made the management of their business immensely more difficult. Last-minute attempts by ministers to persuade Nissan to stay with large investment grants and guarantees of government procurement contracts ultimately failed. The unions could not match the low wage rates in the Balkans. Around 10,000 jobs are said to be at immediate risk by 2029.”

Or this: “The last tenants in some of the City and Canary Wharf’s landmark skyscrapers have declared that they are to transfer to smaller premises in London, and switch some more operations to Frankfurt and New York. They say that the difficulties surrounding access to the European markets have multiplied since Brexit, and that they can no longer justify their presence. The Mayor of London has taken charge of a task force to find new uses for the Canary Wharf Tower, Shard, the Walkie Talkie and other famous buildings.”

I don’t think any of that is alarmist or far-fetched. Yet I also happen to think that the European economy is in serious secular decline, that the single currency and the insistence on completely free movement of labour will cripple its ability to work efficiently and win political assent into the future. Just as we joined the European Communities in 1973 to link to what was then one of the fastest growing economic blocs in the world, so now we must unplug ourselves from a fundamentally flawed project. As in the 1970s in 1980s, the pain of adjustment from leaving will be no less than the pain of adjustment we had when we joined, albeit with the important difference that the UK is much more competitive than it was back then.

But if Europe really is unreformable – and it seems to be so – then there is no reason to stay with it beyond the fact that, I agree, pulling out will be expensive and enormously disruptive. It will be a long time indeed before the UK gains a net benefit from Brexit.

Now I am making assumptions, albeit based on what Theresa May said in her keynote Brexit speech. The Prime Minister outlined what was not being promised, exactly, in the Brexit campaign: no access to the single market, the customs unions, no Swiss- or Norwegian-style “special deals”, no halfway house, no associate membership; just a “bespoke” deal, of necessarily unspecified provisions.