Three of the National Association of Head Teachers 11 regional executives have now officially nominated Mick Brookes, a former president of the union.
The 56-year-old decided to challenge David Hawker, the candidate selected by the union's personnel committee to succeed David Hart, after it emerged that a large number of the committee members were unhappy with all three short-listed candidates.
Both candidates are confident they can win. Mr Hawker, 50, and education director at Brighton and Hove council, is being promoted as the NAHT's official candidate on its website, which highlights his proven track record and suitability for the job.
It describes him as: "A very skilled negotiator who is prepared, when necessary, to take a tough line and stick to it."
But Stephen Dainty, NAHT north west regional president, said part of the reason his region was supporting Mr Brookes was concern at Mr Hawker's lack of recent classroom experience. "He has walked in the corridors of power but we want someone who has come from the heartbeat of the union," he said.
The region was also concerned that all NAHT members should be given a say, rather just the seven on its personnel committee.
Mr Brookes, head of Sherwood junior, Warsop, Nottinghamshire, also has the backing of the south west and east midlands regions.
Gareth Matthewson, chair of the personnel committee, said the election, costing pound;25,000, would be concluded by the first week in April at the latest. All 40,000 members would have a vote and he did not expect there would be any campaigning.
As The TES went press one of Mr Hawker's main headaches in his current job, a long-running pay dispute between teaching assistants and Brighton and Hove council, moved closer to resolution.
Members of Unison and GMB unions, 80 per cent of the authority's teaching assistants, have already been on strike for three days in November and December. But this week after threatening to escalate the dispute with five-day and indefinite strikes in some schools, the unions were understood to be about to agree terms with the authority on going to the conciliation service Acas for binding arbitration.