It used to be a cliché of British public life that left-wing radicals would eventually find themselves transformed into harmless “national treasures.” The Labour politician Tony Benn went through this process of absorption after retiring as an MP, when there was no longer any question that he might exercise power and use it to transform British society.

Many people wondered if Jeremy Corbyn would receive the same treatment after Labour’s defeat in the 2019 general election. However, it looks as if Britain can no longer afford this particular heritage industry in straitened economic times. Nearly four years after he stepped down as Labour leader, any suggestion by a mainstream pundit that Corbyn might not have been so bad after all is likely to provoke a reaction from their colleagues that brings to mind Donald Sutherland’s unearthly shriek in the final scene from Invasion of the Body Snatchers.

The filmmaker Ken Loach has been on the receiving end of similar treatment lately. Loach has just released what he says will be his final film, The Old Oak, at the age of eighty-seven, having contributed to Britain’s film and television culture since the 1960s. A close look at the effort to blacken Loach’s name on spurious grounds tells us a lot about the standards governing public debate in Britain.