Alan Ritchie, the Scottish regional secretary, is the frontrunner for the job, although London branch organiser Michael Dooley has also thrown his hat into the ring.
Other candidates likely to emerge to join the race once the nominations open include John Flavin, a union member, and regional organisers Jimmy Woods from Liverpool and Ron Sinclair from Manchester.
Alan already has a lot of support within the higher echelons of the union
UCATT insider on Alan Ritchie’s candidacy
One union insider said that the race for the election was hotting up, with lots of canvassing taking place by potential candidates. He said: "The general feeling is that it was originally going to be a straight race between John Flavin and Alan Ritchie, but as Mick Dooley has declared himself a candidate the vote could be split."
The insider added that Ritchie was seen as the frontrunner as he had the most experience of being a regional secretary. He said: "Alan already has a lot of support within the higher echelons of the union."
However, the insider added that Dooley had a fair support base and offered a fresh approach to leadership as he is younger than most of the candidates.