"This is history in the making," said one member of the National Association of Headteachers leadership who had risen at 5am to reach central London on time. .
The association's leadership was buzzing with excitement having secured a hastily arranged afternoon appointment with the education secretary, Gillian Shephard.
"We were meant to see (junior education minister) Cheryl Gillan," one explained, speculating that the meeting was arranged at the behest of Downing Street.
Leaving behind them the remains of 500 packed lunches, NAHT daytrippers filed into the historic Westminster Central Hall for a pep talk from their leader, David Hart.
Mr Hart said the Government's proposals, to shift some of the financial burden of retirement before 60 from central to local government effective from March, were a result of pressure from the Exchequer. He said the means chosen - cutting back teacher training and forcing others to work to the bitter end - was the worst of a number of different options.
To warm applause he said that one important matter had been omitted from the debate: "You are paying into a pension scheme and, as a vested interest, must have a say in key issues such as premature retirement."
Suitably stoked by Mr Hart's speech the NAHT task force, warned that they might have a long wait to see their MPs, who were in the Commons for Prime Minister's Question Time, were sent into an animated dress rehearsal.
"My right to manage is being undermined," Neil Thornley, head of Fearns High school in Lancashire, said. "Heads will be obliged to keep on teachers who are reluctant and demotivated.
"55 is a sensible age to retire these days. It's not a question of burnout: teachers are simply different animals these days because the demands on them are changing."
According to Tom Weston, head of a primary school near Crewe, the proposed changes were not only "the worst legislation in the recent history of Government crassness", but also a false economy. "LEAs grant early retirement to heads, deputies and teachers in the interests of efficiency," he said. "All the additional costs of employing older teachers will fall to the schools. "
In a manner more typical of their wards, headteachers, shepherded by an official in an NAHT-issue fluorescent green jacket, made their way in pairs across Parliament Square to wait outside the House. The lobby queue of red-nosed headteachers stretched for several hundred yards and was, according to one seasoned observer, one of the longest in recent times.
For Terry Yarrow, the wait with fellow heads from County Durham was nothing more than a gesture of collegial support.
The 51-year-old head of Firthmore Junior School in Darlington said: "I've worked in a tough school for more than 23 years and won't last until I'm 60. I wanted to give 25 years' service, but if I wait that long I might be without a pension until I'm 60."
Next in line, John Coatman, head of St Andrew's school in Croydon, has already lined up part-time youth work in anticipation that he will receive no pension or lump sum for five years when he retires this year at the age of 55. Striking a conciliatory note, he acknowledged the need to reduce the number of early retirements, but said the Government had been clumsy and underhand.
He called for a gradual introduction of the reforms to avoid a mass exodus, thus enabling schools to plan, and a compromise deal for teachers wishing to retire at 55.
His sentiments were shared by Janet Pidgeon who hoped to impress her views on the member for Enfield South, Michael Portillo. "I've got mixed feelings about that," she confessed.