For weeks, the 35 low-paid and mostly Spanish-speaking cleaners who tend the grand offices of global advertising giant Saatchi & Saatchi have been locked in a bitter dispute to secure what most working people take for granted. They wanted to be paid for the work they had done.

Last Friday, they made a breakthrough when a donor was found to help initiate employment tribunal proceedings – but their campaign for payment of seven weeks’ unpaid wages and holiday money totalling £40,000 has illustrated the vulnerability of millions of workers in a low-wage economy.

Consolidated Office Cleaning Limited (COC) won the tender for cleaning the Saatchi offices in London’s Soho five years ago, competing against four other companies. In September, HM Revenue & Customs initiated court action because the company owed more than £760,000 in unpaid tax and VAT. COC continued to invoice Saatchi for cleaning and when cleaners’ wages weren’t paid in October for the previous four weeks, COC told the cleaners this was a temporary situation caused by moving from one bank to another.

In November, COC began the process of voluntary liquidation – without informing the cleaners, who continued to do their jobs, still without payment. Some were forced to walk miles from home to work because they could no longer afford fares. One woman had to pay £5 a day on fees for a £700 overdraft. On 11 November, the cleaners organised a protest at Saatchi. “The staff organise to raise money for Africa, but for them we are invisible,” one cleaner says.

Liana Florian Gonzalez, 26, has three children under 10. She is owed more than £1,000 in unpaid wages.

Saatchi says it had received repeated assurances from COC that the wages would be paid, even as the company was beginning the process of voluntary liquidation. Kellie Stevens, who signs herself in correspondence as a director of COC, declined to comment. Saatchi says once it understood the situation, Cheshunt-Group Cleaning Services took on the role of subcontractors on 13 November and began to pay the cleaners weekly. However, neither Saatchi not Cheshunt accepted liability for the £40,000 of unpaid wages.

The same week, the cleaners, mostly Spanish-speaking and earning on average less than £1,000 a month, attended a free legal advice clinic in south London that barrister Maria Gonzalez-Merello, herself once a cleaner, has held every Thursday for nine years in St George’s Cathedral, Southwark.

Since then, Gonzalez-Merello and her fellow barrister John Samson, working pro bono, have been guiding the Saatchi cleaners through the minefield of employment legislation. “The cleaners have no resources, no understanding of the system and without money and help, they can do nothing,” says Gonzalez-Merello. “New government procedures mean that getting a claim off the ground is almost impossible, particularly for foreign nationals with little or no English. The fees for starting a claim are huge, the process is almost impenetrable, even for experts, and the law is complicated. It’s exploitation of the very weakest. This happens again and again. In many instances, cleaners walk away with nothing because what else can they do?”

Barrister Maria Gonzalez-Merello.

Samson adds: “Contracting out at murderously sacrificial rates, zero hours and the minimum wage is a triple combination that has a disastrous impact on those who already have nothing while the law does little to help.”

This week, and in case the emerging deal falls through, Gonzalez-Merello and Samson will protect the Saatchi cleaners after the donor came forward to help launch legal proceedings. They will also represent the Saatchi cleaners at a series of hearings and meetings concerning COC’s insolvency.

Gonzalez-Merello at the free law clinic also handles issues such as parents having children taken into care because they are forced to leave them at dawn to go to work, and a sharp rise in solvent subcontractors who refuse to pay wages legitimately owed to cleaners, adding up to hundreds of pounds. “It is unlawful, but many employers do it because they can,” she says. “Only when we intervene is the money forthcoming – but not always. And most of the low paid have no access to legal representation.”

Francisco Javer Horedia, 37, from the Dominican Republic, has cleaned for 15 hours a week at Saatchi & Saatchi for two and a half years. He works another 12.5 hours at Victoria’s Secret in London’s West End. He cannot find full-time employment. His total wage is £800 a month, and £520 immediately goes on rent for a bedsit. A lack of wages has left a huge hole. Liana Florian Gonzalez, 26, has three children under 10. Her unpaid wages are more than £1,000, Christmas is coming and she has been forced to borrow from a friend and her father.

On 13 November, Saatchi paid each cleaner 30% of what they were owed and described this as a gift. The company subsequently said it was an interest-free loan. For weeks, Gonzalez-Merello and Samson have fought to persuade Saatchi to accept liability for the lost wages. As a result of their efforts, last Friday, a deal began to take shape.

Margherite Manghere, 25, works 20 hours a week, and received no wages in June and July.

The Saatchi 35 will have their contracts taken over by Cheshunt-Group Cleaning Services. Saatchi has agreed to indemnify the unpaid wages. In addition, under employment law, continuity of employment will be maintained that keeps redundancy rights for the cleaners intact. Saatchi has also “written off” the 30% payment. Magnus Djaba, CEO of Saatchi & Saatchi London, says: “Though there is no legal reason for us to pay the wages owed to these cleaners, we felt a moral responsibility towards these people, many of whom have been contracted to clean our offices for many years.”

More than 100 cleaners are employed on COC contracts for Publicis, owner of Saatchi & Saatchi. It is hoped, following the intervention of Gonzalez-Merello and Samson, that Publicis will agree to treat all cleaners in the same way as the Saatchi 35.

“Of course people are looking for value for money, but our belief is that staff come first,” says Keith Grosse, a director of Cheshunt. “We will be paying on a weekly not a monthly basis to help the [Saatchi] cleaners catch up. Cleaners are getting up at three and four in the morning for £70 or £80 a week and their bread and milk doesn’t come any cheaper than ours. Then, they get firms that knock them back. That isn’t right.”