It is a small detail of a large picture: last week, a group of would-be journalists received a letter telling them the Mirror newspaper group would not be offering them places on its training scheme.

Cost cuts were blamed for the “temporary halt” to a scheme that produced journalists such as Alastair Campbell. But their disappointment was as nothing to investors’ on Monday, when Trinity Mirror, the parent company, sounded the shrillest warning yet on the outlook for the traditional media sector – and saw its shares fall 28 per cent.