Mr Jarman had spent 36 years in the union with a range of different responsibilities, including being the official in charge of pupil behaviour and special educational needs.
In 1988, he became head of membership and communications - a job in which he showed such propaganda expertise that a colleague later branded him "the Alastair Campbell of the NUT".
But he was not always so powerful. In 1972, as a young district officer, Mr Jarman was contacted by a female teacher at a Wirral school whose head had forbidden her to wear trousers. The embarrassment of bending over in a skirt in front of pupils was too great, she explained, and could he have a word?
The green young officer, who according to union rules was not senior enough for such negotiations, arranged a meeting with the rather conservative head. After some debate, a compromise was agreed: she would be allowed to wear culottes.
The liberated teacher promptly wrote to the NUT's president to express her delight at the deal. But the president was irritated that Mr Jarman had stepped outside his remit, and complained to Sir Ted Britton, the NUT's then general secretary.
Sir Ted ordered Mr Jarman down to London for a telling off - but one delivered with a wry smile.