Come with me on a walk that will ruin your life. It will trash your income and slash your life expectancy by decades, as we stroll from one part of London to another. But it will also demonstrate the gross inequality that is plaguing Britain and that ought to be making people mad at the start of this election campaign.

We start a short distance away, in one of the most privileged parts of the country, never mind London. This is Prince’s Gate, a grand Victorian terrace near the Royal Albert Hall, where planning permission has just been granted for what could become the most expensive private home in the capital.

As super-mansions go, this one looks pretty shabby. The first three houses in the terrace are yellow, like rotten teeth in a row. There is damp growing up the walls of homes that were magnificent when John F Kennedy lived here as the son of the US ambassador; but now they will be magnificent once again.

The Saudi owners want to knock all three through to create one enormous property, with an indoor swimming pool, wine cellar, gym, staff quarters and an underground car park.

With five storeys, an imposing stucco front and views overlooking Hyde Park it will be worth double what anyone has ever paid for a private home in London (at least on the record) – and all within walking distance of one of the poorest neighbourhoods in the country.

“This is prime Knightsbridge,” says Becky Fatemi of the luxury estate agent Rokstone. “If the property was refurbished and converted into a single super-prime mansion, it could be worth anything from £200m to £290m which, at the upper valuation, would make it London’s most expensive home. The Gulf royals would have the money and a trophy property like this would interest them.”

In pictures: The most expensive streets in UK Show all 9 1 /9 In pictures: The most expensive streets in UK In pictures: The most expensive streets in UK 1. Grosvenor Crescent, Belgravia, London - £16,9m Creative Commons In pictures: The most expensive streets in UK 2. Spicers Road,, Oxshott, Surrey - £3,7m google street view In pictures: The most expensive streets in UK 3. Sandbanks Road, Poole, Dorset - £2,5m Creative Commons In pictures: The most expensive streets in UK 4. Park Lane, Altrincham, Cheshire - £2,5m Creative Commons In pictures: The most expensive streets in UK 5. The Ridgeway, Rothley, Leicestershire - £1,8m google street view In pictures: The most expensive streets in UK 6. Newton Road, Cambridge - £1,8m Creative Commons In pictures: The most expensive streets in UK 7. Tiddington Road, Stratford -upon-Avon - £1,3m Creative Commons In pictures: The most expensive streets in UK 8. Runnymede Road, Ponteland Northumberland - £1,2m Creative Commons In pictures: The most expensive streets in UK 9. Rutland Drive, Harrogate, North Yorkshire - £1,2m google street view

The Qatari royal family must be in the market, having been turned down a few days ago for a similar project in Regent’s Park, where Westminster council said knocking two Regency homes into one was out of the question when there was already a shortage. However, permission has been granted for the Grade II-listed Prince’s Gate.

It sits right on the border with the Royal Borough of Kensington and Chelsea, the richest council in Britain, which is even more keen to welcome kings, queens, moguls, tyrants, tycoons, oligarchs and anyone with extreme wealth. The council even offers a discount on council tax if a mansion is a second (third, fourth or hundredth) home.

Yet this is also a place of extreme inequality. There are damp, overcrowded flats not far away, in which mothers and fathers go hungry in order to feed their children. The poverty gap is widening across Britain in a way that should be causing outrage at the start of the election campaign, and nowhere is it more visible than in this part of London.

The richest people living in this country now take a greater share of the total wealth than they did at the start of the century. The top 10 per cent of earners own 54 per cent of total assets, while the top 1 per cent have seen their incomes soar. Nothing demonstrates this better than a walk across Hyde Park from the most privileged neighbourhood in the capital to the poorest.

Prosperity and private healthcare mean that a man living in the lovely terraces around Prince’s Gate can expect to live to 91. Cross the road into Kensington and Chelsea, and the average wage is a staggering £101,000. That’s the median, allowing for extremes of wealth, while the mean is £36,000. But, a walk away to the north, lies Golborne, the most deprived ward in London, according to one measure. Here, the mean average wage is £18,500 and life expectancy for a man is just 72.

Cllr Emma Dent Coad (Micha Theiner)

Among the Moroccan community, that figure drops to 63. “Their health is tragic,” says Emma Dent Coad, who represents Golborne on the council. “I am furious at the inequality here. There is no excuse. The council has reserves of £283m. We have the money to tackle inequality if we want to, but we just don’t want to.”

She talks of seeing parents go without food until they faint, so that their children can eat. She is seeing four-year-olds whose teeth drop out because of vitamin D deficiency. “They arrive at school tiny because they were malnourished in the womb, because the mother could not afford to eat properly. Some of the homes here are Dickensian. These people have nothing.”

Two-thirds of the children in Golborne live in overcrowded homes. Meanwhile, to the south, near the Royal Albert Hall, numbers 13, 14 and 15 Prince’s Gate stand empty. Eight US ambassadors lived here, which explains the Beaux Arts façade, so beloved in Washington, and the stone faces of Native Americans looking down from the window arches.

The three houses were bought for £36m in 2010 by Viridis Real Estate, the property division belonging to the Jameel family of Saudi Arabia (said to be worth £3.3bn). It was a smart move, as property prices here have soared by 65 per cent since then. Such deals are often about keeping money safe rather than finding a place to live.

The best examples of that can be seen as you walk to Golborne, through Hyde Park and past the armed guards on sentry duty at Kensington Palace, to the road that faces the home of the future king. Kensington Palace Gardens is known as Billionaire’s Row. The mansions are immaculate and supercars wait behind huge iron gates. Residents are said to include the steel magnate Lakshmi Mittal and the Sultan of Brunei, who controls a fortune worth £40bn.

According to Bloomberg, with a discount for second-home status, the Sultan paid £1,942 a year in council tax for his house here in 2012: just £32 a month more than the council tax paid by the Braithwaites, a pensioner couple living with their daughter and grandchildren in a rented home in Golborne.

Billionaire’s Row feels very distant, like a different country – but then you exit through the checkpoint and emerge in Notting Hill, once bohemian but now synonymous with gentrification and the films of Richard Curtis, made when this was Cool Britannia and we were promised that “things can only get better”.

Trellick Tower in Golborne was designed by Modernist architect Erno Goldfinger (Getty)

That was certainly true for Tony Blair, who is now a multimillionaire. So is the architect of New Labour, Peter Mandelson, who famously said that he was “intensely relaxed about the filthy rich” as long as they paid their taxes. But the trouble with the new filthy rich in London is that they do not pay their taxes here, if at all.

“Trickle-down is a fallacy,” says Emma Dent Coad in a café beyond the Westway, on the edge of Golborne. “We have gone with that for how many years now? The property bubble started way before this government came to power. Property prices have gone through the roof, as these plutocrats have come from all over the world to live here, but our population is poorer.”

She accuses the Conservative council of spending money on making the streets look nice to attract wealthy incomers, rather than tackling the poverty hiding behind closed doors. “They have sanitised poverty. Disneyfied it. That is not regeneration, they are just displacing the community. It is deliberate.”

There are pockets of resistance. Many of the original tenants still live in Trellick Tower, which looms above Golborne. Designed by Modernist architect Erno Goldfinger, it is either a high-rise monstrosity or a modern marvel, depending on who you believe. “The people who live there love it because the building works,” says Dent Coad, who writes about architecture and planning as well as being a Labour councillor. “I was made in Chelsea. I know there is pride in this community. People may be poor but many of them keep their homes immaculate.”

Not every block of flats is as good as the Trellick; many are a disaster. “Come and look at the stairwell,” says Theresa, a 47-year-old woman I meet on the street. She takes me to a damp, dark and, frankly, nasty place. “Look. When it rains, the water comes through the ceiling, the paint is all blistered there. You walk under it, you get wet.”

The Sultan of Brunei, who controls a fortune worth £40bn, owns property on Billionaire’s Row in Kensington (Getty)

Her friend Frances, 57, says her neighbours are being moved early because black mould has invaded their flat. “Their children are all sick.” Both women have been waiting for years to be rehoused, which is why they don’t want their surnames to be used. “If you say anything against them, they won’t give you a flat.”

There is similar secrecy among the men standing outside a café on the street corner, waiting for Friday prayers. Mo wants to remain anonymous because he is frightened of losing his job as a night guard at a finance firm. I want to ask him something that has been on my mind a lot during today’s walk. Why are there not more riots? Why don’t the people who have nothing get angry and just go and grab something from the people who have too much? “I have thought about this,” he says warily. “The poor always go to jail. The rich people, never.”

Dent Coad is appalled to find that gentrification is creeping north. “There were Bentleys outside the new pub yesterday. What are they doing here?”

But the trouble with all this righteous anger from a Labour councillor is that some would say it was New Labour that got us into this mess, encouraging foreign billionaires to come here in the belief that that would lead to wider prosperity. Ed Miliband was a key part of an administration that unashamedly cosied up to the super-rich, which may be why he has failed to speak up clearly against inequality so far in this election campaign.

“I’m not New Labour and never have been,” Dent Coad says. “What motivates me, drives me to a fury, is social injustice. If something is wrong, we have to fight it.” Even if there is little chance of success, in a city seemingly besotted by super-wealth? “You’ve got to have a dream, mate.”