It could hardly have been more insensitive. On December 21st last, four days before Christmas, an average of £350 was docked from the salary cheques of all members of the Association of Secondary Teachers, Ireland (ASTI).
The money was deducted in relation to "work-to-rule" days in November when ASTI members reported for work as normal but withdrew supervision cover. During those days most schools were forced to close for safety reasons.
Traditionally students have been supervised on what teachers say is a "voluntary" basis. Despite pleas from management bodies and others, the Department of Education has consistently refused to introduce proper supervision structures.
It has refused to pay teachers for a job which is an essential part of daily school life. And it has refused to follow the example of countries such as France, where teaching assistants are recruited for these non-teaching duties.
Against this background, any decision to dock pay for the work-to-rule on supervision was always likely to prove controversial. But the Government's decision to proceed with the docking of pay when peace moves were in train turned a potential drama into a fullblown crisis.
In the process, it also helped to revive the ASTI campaign for a 30 per cent pay increase, which had been roundly criticised both within the union and outside it.
The money was docked just days after the union and the Government had agreed to the appointment of a mediator in the dispute, Mr Tom Pomphrett of the Labour Relations Commission.
This had been widely seen as marking, if not the end of the dispute, certainly the beginning of the end.
Mr Pomphrett's appointment helped to lower the temperature in the dispute; there was no longer any apocalyptic talk about a threat to the Leaving Certificate examinations. There was confidence that a deal could be cobbled together.
His appointment represented a minor victory for the ASTI, which had been seeking some kind of third-party intervention in the dispute.
In truth, it also represented something of a lifeline after three months in which their dispute had failed to make the desired impact.
The union had failed to draw support from the other teaching unions, it had seen public support slip away, and it had been widely criticised for failing to develop any kind of coherent strategy. In boxing terms, it had failed to land a glancing blow - let alone a knock-out punch - on the Government.
The timing of the decision to dock money - and the crude manner in which it was done - changed everything. With breathtaking insensitivity, pay was docked from virtually all ASTI members.
Principals and deputy principals who had worked normally on the days in question had their pay docked. Teachers who had reported for work and held parent/teacher meetings had pay docked. Worst of all, those who were sick or absent found their pay docked.
This, just four days before Christmas, helped to radicalise the most mild-mannered and moderate teacher. The ASTI president, Mr Don McCluskey says: "In my 30 years' teaching I have never known such anger in the staffroom."
This kind of response had been predicted by Mr Charlie Lennon, the moderate ASTI general secretary. Working closely with Department of Education officials, he had invested huge energy in building a peace process.
In the days before December 21st, when pay was due to be docked, he pleaded with Government officials to hold off.
Officials in the Department of Education were alive to these concerns, but the Government was not for turning. The Cabinet had decided to dock the pay at its previous meeting, after ASTI had threatened the examinations, but before the appointment of a mediator. The decision could not be reversed.
The hardline reflected thinking in the Department of Finance that the ASTI needed to be taught a lesson. The Government had spent months shoring up the new partnership deal - the Programme for Prosperity and Fairness - but ASTI had sought to undermine it. Viewed from Merrion Street, ASTI had placed itself beyond the Pale: it deserved a bit of stick.
The Government's decision to dock the pay has boosted the position of ASTI militants - led by the powerful former president, Ms Bernadine O'Sullivan. It made it easier for them to convince others that the Government is the enemy. One said: "Look what happens when we co-operate with their peace moves; they screw us in every way they can. We are better off holding a hard line."
It also helped the militants to change the goalposts in the campaign. The focus is now fixed firmly on a refund of the docked pay.
The dispute is deadlocked as the Government considers the ASTI's demand for a full refund with no strings attached. The Government will refund the money only if ASTI accepts it had a right to withdraw the money in the first place.
Unless a compromise can be worked out the next phase of school closures will begin next week and a ban on examinations will take effect from early next month.
Amid all of this it is easy to lose sight of the fact that the docking issue is no more than a side show. The real issue remains ASTI's claim for 30 per cent, and how this should be advanced.
The union's bottom line on its pay claim is still unclear. It still has no coherent exit strategy. This weekend the militants within the union believe they have won an important battle with the Government by holding the line on pay docking.
But they have still to show that they can win the war.