As workers began to challenge the power of capital and employers at the start of the industrial revolution, trade unions were simply made illegal by the Combination Acts of 1799 and 1800. As with every law since, they hindered action but did not entirely prevent it.
The Combination Acts were repealed in 1824, but another act in 1825 prohibited collective bargaining and made strikes effectively illegal. That was swept away in 1871 by an act legalising the status of trade unions and (on paper) decriminalising strikes, but it left strikers open to prosecution for criminal conspiracy.
In 1901 the infamous Taff Vale judgement ruled that a trade union could be sued and compelled to pay damages for taking industrial action. That ruling lasted five years, until overturned by legislation following the 1906 general election.
After World War Two, Labour governments invited trade union leaders into the corridors of power, hoping they would keep their own members in check. That was only partly successful.
The Labour government’s 1969 White Paper In Place of Strife proposed a return to coercion. Opposed by unions and workers, it was never enacted, but formed a template for the Conservatives’ 1971 Industrial Relations Act. The next Labour government replaced that with the 1974 Trade Union & Labour Relations Act, without the worst excesses of the 1971 Act but still based on In Place of Strife.
The 1980s Thatcher government passed no less than six acts increasingly restricting unions’ ability to take lawful industrial action. Secondary action was outlawed and pickets were restricted. Secret ballots were mandated, and from 1993 had to be postal.
The increasing complexity of trade union law gave employers the opportunity to obtain injunctions to stop union action, and the means to sue unions for damages.
Despite union pressure, the Blair/Brown Labour government failed to repeal any of the previous anti-trade union law. The return of the Conservatives to power saw a further Trade Union Act in 2016, the current legislative position.
• Related article: Trade union laws: a brake on workers' action