bet the bank on the May 2014 European elections. We may have made British political history with our victory on the night of Sunday May 25, beating both the Conservatives and Labour, but we were also broke – again. I had spent all the Ukip funds on winning at the ballot box, bar about £6,000.

I love a gamble, I love stacking up the odds, and it has only been through taking enormous risks that the party and I have got to where we are today. It was as a commodities trader in the City of London that I learnt how to calculate and assume risk. Not only did trading in the City help to whet my appetite for taking a gamble, it taught me how to get out when the trade started to go wrong, and to brush yourself off when the losses started mounting up.

I went into the City at the age of 18, straight from Dulwich College, following in my father and grandfather’s footsteps. I got a job working for a metals trading business and spent my days buying and selling aluminium, copper, zinc, lead, nickel and tin. Trading metals can be big money, big risk, and a huge amount of fun. There is the risk that you may not make much money on a trade – and the risk that you may lose a small fortune.

One morning in the early Nineties – by then I’d been working in the City for a decade – I lost a seven-figure sum in the course of a morning on the zinc market. Not a good day, and it was only lunchtime. Contemplating the sobering loss I had just run up, I grabbed my jacket to head out into Broadgate, with the aim of being less sober while I considered just how much I was down.

‘‘Where do you think you are going?’’ my boss yelled after me. ‘‘Out to lunch,’’ I replied, “but if you want me to take my jacket off again and stay put, I can start losing the same amount this afternoon, if you’d rather.”

The City I started work in on September 1 1982 was a world away from the City as it is today. Maclaine Watson & Co Ltd, a 19th-century metals broker, offered me my first job as soon as I had finished my A-levels (which were pretty unremarkable).

The trading room – full of cigarette smoke, smart suit jackets on the backs of chairs, and long desks packed with multi-line phones – was close to the London Metals Exchange and, God help us, to Coates wine bar where we often went at 11.30 in the morning for sharpeners.

I liked the mix in the City; nobody cared how posh or rough you were; you were rated on how much money you could make. My first job was in the so-called “back office”, processing the transactions, and it was deathly dull. But the magical door of the City had been opened – and I had walked through it.

One of the myths to have emerged from the financial crisis of 2007/08 is that the City is full of men who make eye-watering amounts of money and do very little. Actually, a huge number of people put in very long hours, commute in conditions that are Third World, work under an enormous amount of pressure and are forced to live in the most expensive part of the UK. Few of them earn a fortune and, even now, it is a really hard-working sector.

I started on £4,000 a year, and after my first year I got paid a bonus of £300 in 1983. I was very chuffed. My first five years were fantastic fun. When it was busy you worked hard, when it wasn’t you went for lunch. It was alcoholic like you cannot believe and, frankly, we were pretty amateur. There were terrible cock-ups in the afternoon as a result; contracts bought instead of sold, some priced wrongly (decimal points and all those zeros can be tricky after a three-hour lunch), the wrong metal bought for the wrong client. When the mistakes came to light, usually the next day, we would just shrug our shoulders and say: “It happened after lunch.”

It still shocks me how many of my contemporaries and friends did not make it to 50, due to a combination of stress and booze. Burn-out, as it is known. But, despite the long-term cost to your health, the lure of a proper lunch in the City was very great. When the markets were quiet, the trading room would just empty. Lunch was Simpson’s Tavern – a fabulous 18th-century chophouse hidden down an alleyway off Cornhill, which served mixed grills, sausage and mash, bubble and squeak, all washed down with pints of Young’s bitter and a bottle or two of red. Or Sweetings – the most charming of fish restaurants near the old Mansion House. No bookings taken, it was heaving with smart brokers. Turn up, share dining tables, order your oysters and all that. It was like being back at school – but with money.

On busier days I’d nip out to The Lamb in Leadenhall Market for a few pints of Young’s and a roast beef roll. When it was really busy, you didn’t go anywhere. In the Eighties things hadn’t really changed much since PG Wodehouse’s book Psmith in the City. The character created by Wodehouse – like me, an old boy of Dulwich College – said that people in the City spend their mornings choosing where to go for lunch, then their afternoons telling everyone how good it was. When I took my American clients out, lunch was 12 till 12; that’s what they liked.

By the mid-Eighties, I’d become a pretty good trader, broker and market-maker. I remember getting in some pretty tight spots and thinking quite a few times: ‘‘Good grief, where is all this going?’’ If you called the market wrong, you could quickly find yourself sitting on a substantial loss. It taught you how to really hold your nerve, as well as admit when you had messed up. They were lessons that I would need for a career in politics.

But the days of old-fashioned broking were about to change beyond all recognition. And not for the better. By the time that Big Bang came along in 1986, the City was on a path that would eventually see overseas players control Britain’s biggest industry and ultimately hand over control of it to Brussels. Big Bang – so called because the transformation it brought about was explosive – was a change in the rules that governed how the City did business. The then prime minister, Margaret Thatcher, effectively opened up the City to foreign banks, who were allowed to do everything – buy and sell shares for clients, trade for themselves and trade with each other.

Along with Big Bang we had the Financial Services Act of 1986. That piece of legislation introduced a regulatory culture of box-ticking, rather than leaving people with considerable financial expertise to police the City. It was the birth of a culture that would wreak financial devastation to our banking sector two decades later.

The Act brought in ghastly regulators, who were supposed to police the City and make it safer for people to do business. But the vast majority of those regulators – God, I hate those people – had failed in the City. They just did not understand what bankers and brokers were up to.

From 1986, I was asked to produce such things as risk assessments, and would just refuse. It was like Health and Safety for derivatives. The whole point of the City is to take and manage risk, and I had no intention of filling out a form to tell the compliance department – by then the fastest growing part of the business – how big the risk was. Compliance departments changed the whole culture of the City. Apart from monitoring everything, we had to start minding our Ps and Qs. They basically took the fun out of trading – and they also missed the point. While compliance departments were getting us all to tick boxes, they failed to register that a derivatives industry was growing exponentially under their noses, an industry dealing in products they did not understand and with a risk profile they were oblivious to.

Do I miss the City? On bad days, do I yearn for the adrenalin, the buzz and the camaraderie? I miss what it used to be. I would loathe it now. Þ