Today, the average British trade unionist is a young, degree-educated, white woman working in the professions. Women outnumber men. In their prime in the 1970s, unions had more than 13 million members. Now, they have 6 million; only 28% of the working population is unionised – less than 20% in the private sector. Women have become vital to the survival of unions. In a yet more extraordinary change, this autumn, the Trades Union Congress (TUC) the umbrella body for 54 affiliated unions, will welcome Frances O’Grady, 52, its first female general secretary in 144 years. “We like to take our time,” she says.