According to Forbes magazine, Mexican Carlos Slim is the world's richest man.

But consider this. An adviser to Sheikh Mohammed recently let slip that his boss had spent a mere 4% of his total personal wealth on his passion for horse racing.

By City Spy's reckoning, the ruler of Dubai has spent £10 billion on his hobby in the last 10 years. That may be a conservative estimate — the Sheikh has more than 1,000 horses in training and countless broodmares and stallions stabled at his worldwide stud farm empire.

If it's remotely close, then the Sheikh has to be worth £400 billion. Maybe it's time for the people at Forbes to re-assess.

Caroline has a City following

Gordon Brown, in his “I will go on” interview with Radio 4's Woman's Hour yesterday, was asked about his attitude to working with the fairer sex, after ex-Europe minister Caroline Flint claimed Brown treated women in his Cabinet as “little more than female window-dressing”.

Brown insisted: “No, I feel more comfortable with women, I've got to tell you. Right throughout my life I've worked very closely with the women who've worked with me. Some of the most senior people working with me are not only women, but extremely, extremely professional and competent women.”

But what is La Flint doing now she has so much time on her hands after quitting the Cabinet? She is admired in City circles — she has served at the Departments of Trade and Industry and Work and Pensions — and is also well-connected in the retail sector...

Knives out for Unite's Charlie Whelan

Colin Byrne, the boss of PR firm Weber Shandwick and former spin doctor for the Labour Party appears too have reservations about the role in the Party's campaign being taken by his old colleague Charlie Whelan.

The former Brownite Treasury spinner, now a big wheel in the Unite union, is said to be back advising Gordon Brown. “What the hell is a strike-mongering politically discredited nutter like Charlie Whelan doing at the heart of Labour's election campaign?” asks Byrne on Twitter.

The big winner at Cheltenham

Hats off to Andy Stewart, backer of today's Cheltenham opener.

The multi-millionaire broker and founder of Cenkos has put the Supreme Novice's Hurdle in the name of Spinal Research following the terrible injury suffered by his son Paul while snowboarding in the Alps. Paul, who was told he would never walk again, is making a slow but remarkable recovery, and can now walk with the aid of sticks.

In an interview to mark the start of Cheltenham, his father, who dropped out of school and sees himself as a “massive outsider” in the City, goes on to lambast the Establishment. “One thing that I've noticed in all the disasters in the markets over the last few years is that a lot of the people who have actually been responsible have been overtrained, overqualified or both.”

Stewart is that rarity: a City boss involved in jump racing. He won't have it any other way. “I remember once at Deauville, one of the top Flat owners had a party to celebrate a winner and, when I asked where he was, it turned out he'd gone to bed at seven o'clock. Seriously, what's the point of that? But on Tuesday [of the festival last year] we were at JP McManus's party with the great man himself, singing Wichita Lineman at two in the morning.”

I have an Olympic dream

Yeah, yeah. Andrew Wyllie, of construction giant Costain, was running a 10-kilometre race that passed around the London 2012 Olmypics site. “As I was running I was thinking about how the Olympics is all running on time and on budget, and I thought, what a great advert for the UK construction industry.”

Berry's first-class mistake

Farewell Anthony Berry, scion of Berry Bros & Rudd. City Spy loved the tale of how, after he retired as chairman of the family wine merchants, Berry still liked to attend board meetings. He was uncommonly late for his first one after moving to the West Country. The reason was that he'd been delayed at Paddington, waiting for a tube train with a first-class compartment.

Gamekeeper lectures poachers

A flyer lands from law firm DLA Piper aimed at Britons with money abroad that the taxman is keen to know about. DLA Piper's Simon Airey and Aileen Barry will be running seminars up and down the country. Somewhat oddly, the two-hour seminar starts with a representative from HMRC outlining the Revenue's perspective — perhaps while another takes names and addresses.

The naked press officer

Jamie Oliver's book is due out next month. No, not that one, but Jamie Oliver, a press officer for UK Trade & Investment. He's co-authored “How They Blew It: the CEOs and entrepreneurs behind some of the world's most catastrophic business failures”.

Diets out on the silver screen

From Cineworld boss Steve Weiner. “People even forget their diets when they go to the movies - in supermarkets, sales of normal Coke and Diet Coke are about the same. At our cinemas, normal Coke sales are much higher. The cinema is another world.”

Digging down for good news

Things are looking up. Spiral Cellars, which sinks wine cellars into the floors of the homes of the wealthy, says trade is booming as bonus-fuelled City folk splash out on storage for their vino.

Money magicians

“Management consultants add £56 billion of value to their clients” trumpets a survey carried out by the Management Consultancies Association.