Britain’s recent rail strikes mark the first time since 1989 that workers across the entire network have been in dispute with their employers. But for much of the past decade, passengers across the country have faced severe disruption thanks to industrial unrest. Guards on Northern, the franchise which covers much of the north of England, were in dispute for an entire year, while a parallel clash on Southern, which operates commuter services south of London, lasted even longer.

What would motivate any group of workers to take such sustained strike action? After all, striking is a risky business: there are no guarantees of winning, you may be disciplined by management for taking part and each day you are on strike is a day’s pay lost.