While the 60 RMT members finally gained recognition through a tribunal, which declared that the evidence presented by the contractor Churchill bore "little relation to the reality of what had actually been happening," the seeds of their triumph lay in their unity and determination to win justice.
Equally important was the readiness of their union to throw its resources behind this struggle by low-paid workers.
Workers join trade unions because they understand the need for collective security. Individuals can be picked off by ruthless managers and pay claims ignored as a potential drain on corporate profits.
But when a workforce decides that it has taken enough and its union leadership elects to mobilise widespread solidarity, apparent weakness gives way to collective strength.
Churchill is one of those service conglomerates that has been successful in mopping up contracts to provide services to other companies that were previously delivered by directly employed staff.
Tyne & Wear Metro once provided a publicly owned and operated service to passengers in the North East, employing all staff directly on union-negotiated conditions.
But neoliberal orthodoxy, with its flawed but persistent prejudice that private profit offers greater efficiency than notions of community and public service, dictated privatisation and contracting out for this transport system financed by the people of the region.
Regional transport authority Nexus handed the contract for the Tyne & Wear Metro system to Deutsche Bahn Regio, a fully owned subsidiary of the publicly owned German state railway system.
How ridiculous that political hostility to the public ownership of Britain's railways should be expressed by engaging another country's public rail company to run the system here for a profit to be invested in better services in Germany.
The same applies to French-owned Arriva and subsidiaries of Portuguese, Belgian and other public networks.
Deutsche Bahn Regio is not interested in employing ancillary staff such as cleaners, so it engages contractors such as Churchill and its predecessor Connaught whose profitability is enhanced by squeezing the living standards of its workforce.
In fact, the only time directly employed Deutsche Bahn Regio staff cleaned Metro stations was when its managers joined their Churchill counterparts to scab during strike action to undermine the RMT members' action.
Churchill proclaims on its website: "Our cleaning teams are characterised by their approachable, assertive and professional nature in delivering a sustainable, efficient and customer-focused solution," which suggests that workers are worthy of respect.
But that was far from the case with its employees on Tyne and Wear Metro, many of whom were paid the minimum wage and denied additional payments for working on Sundays and bank holidays.
Despite efforts by Churchill human resources manager Debbie Wakes to persuade the tribunal that this mirrored the Connaught contract, which would have undermined the workers' case based on transfer of undertakings legislation, it decided otherwise.
A further tribunal hearing will be held towards the end of the year to establish how much the cleaners have lost since 2011 when Churchill took over.
Their windfall could amount to £2,000 apiece, which will be welcome, but even more valuable than this early Christmas present is the recognition that trade unionists can still win key victories despite all obstacles thrown up against them.