The national strike planned for 30 November has been described by the public sector unions, with some justification, as "the biggest industrial action in a generation".
With the three main classroom unions - not to mention Unison and Unite, representing support staff, and the University and College Union - likely to be on board, and thousands of schools and colleges expected to close their doors, the spotlight now falls on the heads' unions. Could we really see principals across the country going on strike for the first time?
The evidence so far suggests so. The NAHT begins its own ballot next week, and Association of School and College Leaders (ASCL) general secretary Brian Lightman has already admitted that it is "certain" to follow suit, should the ongoing talks with the Government fail to yield an acceptable compromise.
But school leaders will have to balance their fears for their own nest egg and loyalty to their staff with concern for their pupils' education and the school's standing in the community. The decision will be anything but straightforward.
Despite having never taken part in a strike before, Steve Iredale, head of Athersley South Primary School in Barnsley, is reluctantly steeling himself for action. The NAHT vice-president describes the pensions issue as a "defining moment" for the profession, which has inflamed the traditionally moderate union.
"I want my kids to be in school, and their parents to know they are here. I am not a striking person, I never have been. It won't come easily to me, but I have absolutely no doubt that I will be going on strike, if it comes to it," he said.
"The parents have a grasp of it. They won't like it, and I will be on the end of attacks from certain angles in the community, but a line has to be drawn in the sand."
While Mr Lightman has no doubt that ASCL members, too, are furious at the plans to change their pensions, there is a broad spectrum of opinion on what action - if any - they should take. "All the unions are in complete agreement in condemnation of what the Government is doing on pensions," he said. "A lot of heads are torn between that and the responsibility they have towards keeping the school open and providing an education to their pupils. It's a predicament which is a very personal one."
Steve Woodhouse, head of Sutton Upon Derwent primary in East Yorkshire, expects that, come 30 November, he will be the only member of staff in work. But, while he is fiercely opposed to the changes to teachers' pensions, as a paid-up member of non-striking union Voice he is adamant that he will be at his desk.
"I am firmly behind the unions in opposing the changes, but one of the reasons I joined Voice was because of its position on strikes. There are a lot of things to weigh up. I work in a village where we have had strikes in the past, and the villagers were very negative towards staff who did strike," he said.
But the message from heads' offices elsewhere is, perhaps surprisingly, pro-action. As an NUT member, Simon Cattermole, head of Stamshaw Junior School in Portsmouth, took part in the 30 June strike. He is fully prepared to do it again. "Striking is always a last resort, but on this particular issue we feel extremely strongly that we need to protect one of the benefits of coming into teaching."
NAHT general secretary Russell Hobby senses that many of his members are leaning towards taking direct action. "Many of them feel they are acting to protect their younger teachers, who would be affected by this. They have to balance their concern for pupils with their concern for the future of the education system. Everyone has reluctance to go on strike; it's a question of how far they are prepared to go."
Behind every head's decision on whether to go on strike lurks profound soul-searching. Ministers are quick to portray those looking to take action as impressionable professionals who have been manipulated by the posturing of self-interested, left-wing agitators. It's hard to imagine battle-hardened heads being bossed around by anyone.
The sight of suited principals taking to the picket line would send out a powerful message to the public that perhaps all is not well in the state of education.
A separate wave of industrial action could be on the cards in sixth-form colleges. No pay offer is on the table for teachers or support staff, owing to what the Sixth Form Colleges' Forum described as "unprecedented" cuts.
School teachers face a pay freeze this year, but the classroom unions believe this is a perfect opportunity to start restoring pay comparability between the sectors.
In a letter to members, NUT general secretary Christine Blower wrote: "We need to start to build support NOW for a strong response to the employers, including if necessary a 'yes' vote in a ballot for strike action on pay."