He claims to be heartily sick of reading in newspapers that he is the “intellectual darling” of the NUT left, however Mr Murch is the acknowledged brain behind much of the factional manoeuv- ring that goes on at NUT Easter conferences.

The quietly spoken 55-year-old believes he has personally drafted more conference policy than anyone else in the union. Since being adopted as the left’s official candidate he has used hustings meetings to deliver a careful analysis of the loss of the NUT’s ability to campaign. But he faced a major battle just to get that far. The withdrawal of John Illingworth, a Nottingham head, from the contest in October prompted a period of internecine strife that would not have looked out of place in Monty Python’s The Life of Brian.

But by January he had emerged with the backing of both the Campaign for a Democratic and Fighting Union (CDFU) and the Socialist Teachers’ Alliance.

Mr Murch joined the NUT in 1973, has been Bradford branch secretary since 1981 and national executive member for West Yorkshire since 1986.

He was one of the main founders of the CDFU in 1988, set up to oppose plans to restructure and centralise the union. Members are sometimes dismissed by their opponents as “Trots” but Mr Murch describes his politics as Old Labour.

In 1989 he stood for general secretary but was beaten by Doug McAvoy. He ran into trouble in 1992 when, having been elected as national treasurer, he appeared on a TV documentary that looked into alleged “excessive secrecy” in the NUT. His subsequent suspension was eventually overturned but only after he took his own union to the High Court.

Mr Murch was born in Liverpool and educated at Birkenhead school, then a direct grant grammar. He read economics at Cambridge and gained his PGCE at Madeley college, Cheshire before teaching history and economics at secondary and middle schools in Bradford between 1973 and 1993.

He has six children, and enjoys listening to blues music and visiting France. Ladbrokes is quoting him at 31 and William Hill 61.