THE CLOSED SHOP

The "closed shop" was a controversial practice whereby workers were barred from certain jobs unless they belonged to a particular trade union. it was thought by many, although by no means anti-union,  that the closed shop was a destructive force at a time when some people felt that British unions wielded too much political power. The closed shop was later outlawed by legislation and union power severely curtailed.
Brought to mind by the current issues in the Labour Party.