Johann Hari: The rebellion of Britain's hidden army of underpaid cleaners has finally begun

This is not merely a matter for your conscience. It affects your health, too

Welcome to a Tale of Two Cities. Over the past fortnight, the hymns to London have been endless and gorgeous - but few have acknowledged that this is a megalopolis with a dirty secret: we are not one city at all. There is Daytime London, which arrives at work at 9am to find its offices clean, its bins empty and its carpets cleansed. You know this world. Its inhabitants have an average wage topping £25 an hour. They go to theatres and movies and bars, and easyJet to every corner of Europe. They congratulate themselves daily on living in the most ethnically and socially mixed city on earth.

But there is another London that wakes in the night. It staggers on to the night bus at 4am to filter across hospitals, schools, and the temples of global finance and media to collect our rubbish and dispose of our crap. The average wage is under £5 an hour. The people who live in this other London do not go to theatres or cinemas or on holiday - they cannot afford it. They have been inhaled by London's economy from Africa, South America and every poor country in the world, and they see our self-congratulatory multiculturalism as a bitter joke. Thank you, thank you for letting us come here and skivvy for you 12 hours a day for less than a fiver an hour. How tolerant you are.

In February this year, something extraordinary happened: the London of the night began to rebel. Starting in Canary Wharf, a wave of cleaners' strikes across Britain has forced up the wages of some of the country's poorest people - and today, it hits the heart of our democracy: the Palace of Westminster.

Evrad Ouale is a 27-year-old from Ivory Coast who has cleaned in the House of Commons for four years. He lives in a dingy single room with his wife, and has not left the M25 area since he started the job. He scrambles for overtime, working 60 hours a week, but he admits that even when he is working ever conceivable hour, "You can barely live. It's horrible. We have no choice but to strike. We cannot continue like this".

The way they are treated in Parliament is a grim metaphor for the way most of Britain's 1.5 million cleaners live and work. Their designated area is a filthy Dickensian basement plagued by rats and the stench of the Palace's sewage. Unlike parliamentary researchers or security guards, they are banned from entering the lavishly subsidised House of Commons restaurant between noon and 3pm, as if they were part of an Untouchable caste. They are given 12 days' holiday - that's 12 - a year, and paid £4.85 an hour. If they were British citizens, they would be entitled to have their wages topped-up through the government's excellent Family Credit. But since almost all the cleaners are migrant workers, they are forced to live at rates everyone admits are way below the poverty line.

And within Parliament, the policy that has driven down the numbers and wages of cleaners over the past 20 years can be seen in all its fetid glory. The cleaners in the House of Lords are directly employed by the state, while responsibility for employing cleaners in the Commons has been contracted out to private companies who are paid a bulk fee to provide the service. The difference is a slap in the face: in the Lords, cleaners start at £7.89 an hour, receive a decent pension, and get 30 days' paid holiday a year - a package that seems utopian to their contracted-out neighbours in the next chamber.

Does anyone need a clearer illustration of what happens when cleaners are contracted out? Study after study has found that there are no "efficiency savings" contributed by the privateer middlemen. No: they simply slash the wages of the poorest people (or lay off swaths of cleaners) and pocket the difference.

This isn't merely a matter for your conscience. It affects your health, too. Since contracting-out began to tear through our public services in the early 1980s, the number of cleaners has nearly halved - and the rate of hospital infections has soared.

So it is time to learn how our cleaners are treated, in both the public and private sectors. The workers' rights organisation NoSweat interviewed a number of cleaners who toil in Canary Wharf - our little chunk of New York scraping the sky - in January. One typical African woman, Marcia, explained how her 12-hour day panned out: "We are not allowed lockers because we might steal something and hide it there. When we leave in the morning we are searched by security men. There are no women security officers."

Once she arrives at work, she is strictly forbidden from having any further contact with the outside world. She is not allowed to take in a mobile phone, and she is not allowed to use the phones there. "So, if the kids are sick, I can't ring home and check if they are OK. And once we start work, we are not allowed to rest. There is a supervisor or team leader behind you all the time. Apart from in the break time - 30 unpaid minutes - we cannot sit down". For all this, she receives a few hundred pounds a week to live in central London and raise her kids.

So should we simply despair? Are Britain's cleaners condemned to poverty wages, a level set solely by The Market and never to change? No. Until this year, many people argued that an industry like cleaning is impossible to unionise: staff turnover is a revolving door, the workers speak little English, the workforce is fragmented and demoralised. But the Transport and General Workers' Union (T&G) has proven that this is a myth. Within a few months of recruiting, nearly 80 per cent of workers for Emprise and Mitie - two of the main cleaning firms in Europe - were paid-up union members. Starting in the Canary Wharf complex, they began to demand a living wage at the towering sum of £6.70 an hour, along with decent holiday time, sick pay and working conditions.

And it worked. Barclays agreed to meet the demands, and now most companies in the Wharf have matched them. According to the T&G, only a shamed handful now refuse to pay a living wage - the Bank of America (annual profit: $2bn), Credit Suisse ($3.9bn) and Lehman Brothers ($672m).

The excuse offered by neo-liberals for paying poverty wages - that it drives companies abroad - is exposed as a sham: are banks going to fly in workers from Bangalore to empty their bins? And anybody who claims that there is no need for trade unions anymore should be dragged to speak to the Canary Wharf cleaners - and the cleaners still fighting for a living wage.

As the capital's cleaners begin to strike, I think it is time to end London's self-congratulation about our ethnic diversity. I love London and its spirit over the past fortnight, too. But while you are standing on carpets cleaned by hidden-away black and Asian people who earn a pittance for the privilege, please don't tell me this is a multicultural paradise.

j.hari@independent.co.uk