Our trade unions were kneecapped by Thatcher back in the 80s. A Labour government introduced the minimum wage, but the current Conservative government is progressively increasing it from £6.50 in 2015 to £9 by 2020. Employment tribunals were introduced in 1996 by a Conservative government; a Conservative government introduced relatively high fees in 2013, but this was overturned by the Supreme Court last year.

Unions are part of the picture, but they're a reflection of a broader political culture. Trade unions can't turn the electorate socialist, but a socialist electorate can build strong trade unions.