It would be foolish to underestimate the threat that these militants pose to educational reform. A disturbing vision of our future can be found across the Atlantic where teaching unions have, for nearly 20 years, successfully battled against school reform. Their greatest triumph occurred two years ago when they claimed a particularly impressive scalp: the reforming chancellor of Washington DC's schools, Michelle Rhee, the poster-woman for educational reform. In 2007 she inherited a school system that was in total collapse: only 8 per cent of eighth graders (13-14 year olds)were proficient in mathematics. She challenged the status quo especially the lack of teacher accountability — more than 90 per cent of teachers were recieving good marks. Rhee set about overhauling the system. Out went tenure laws and in came new performance reviews and performance-based pay. Soon 241 poorly performing teachers had been dismissed.

Although she was chancellor for only three years, Rhee was able to pass enough reforms to revolutionise education in Washington. Under Rhee, fourth-grade students' attainment in reading and maths doubled. Teacher absenteeism has declined dramatically and Rhee's ideas for evaluating teachers are now accepted by the DC educational establishment.

Yet the unions' leaders had the last laugh. Enraged by her willingness to dismiss so many teachers and realising that her reforms could only happen with the blessing of the Mayor of Washington, Adrian Fenty, the unions set about trying to dislodge him. During the 2010 primary elections the American Federation of Teachers spent nearly $1 million to help unseat the mayor. Their contribution made a difference: Fenty lost his job and Rhee was forced to resign, her reforms only half completed.

Rhee, who now heads the advocacy group StudentsFirst, visited Britain earlier this year, and took part in a televised debate with Mary Bousted, general secretary of the Association of Teachers and Lecturers. "It was a little baffling," Rhee mused. "I thought we were going to engage, but the conversation simply became personal." She considers the unions' tendency to personalise and demonise an obstacle to educational reform. "It means that you end up with debate on polarised extremes. It means that you are never able to have deep conversations because it all becomes very personal." She believes the only hope is to make sure that parents and union members understand the reforms. "You need a system that is fair and transparent. People will support that." 

Her words should offer some comfort to Michael Gove, who in his two years as Education Secretary has done more to revolutionise the English schooling system than any minister since Rab Butler introduced universal secondary education in 1944. Under Gove more than 700 maintained primary schools and around 45 per cent of all maintained secondary schools are converting to academy status, joined by 79 new free schools. The furore over the harsh marking of this summer's GCSE English papers might have heralded damnation for a less able Education Secretary, but Gove's claim that such irregularities are the inevitable product of a low-quality modular exam system is a bold move, providing the impetus for introducing long-overdue reform of GCSE exams and the reintroduction of more rigorous O-level-style papers. Further bold reform looks likely.