But the primary heads have had victory in their sights since the McCrone committee came out in their favour. The law may not regard McCrone's recommendations as relevant to the equal pay case, but backing from the independent review in May removes the heads' concern that their case would be seen as entirely self-interested.
Bill Milligan, president of their association, is anxious to play down the short-term consequences of a decision in their favour. With estimtes of the national cost running close to pound;200 million, it would indeed be unwise to be seen to claim a mammoth chunk of any post-McCrone package. That would endear the heads to no one, not even their own staffs. So Mr Milligan points out that most primary schools are small by comparison with secondaries and so few primary heads would achieve secondary-level salaries. (The argument about whether a big or a small school offers the greater management challenge is one of the points that divides spokesmen for the two sectors.)
A second reason why the national education budget would not implode is that the primary heads talk of phasing in. The question is over how long a period, and what the expectations would be of back pay, including to retired heads. Mr Milligan's troops may scent victory. Their campaign could still prove long and difficult.