Until this month, few outside the National Union of Teachers had heard of Christine Blower.

But the untimely death of Steve Sinnott thrust her into the spotlight as the union’s acting general secretary just days after it announced it would hold the first national teachers’ strike in 21 years.

As Ms Blower prepared to lead thousands of teachers on the walkout yesterday, she was fired up by by the “vilification” of her and her members.

The retiring head of the statutory teachers’ pay body had told The TES that the strike was costing teachers public respect. A newspaper had also described Ms Blower as a “radical” pushing for strike action.

“Teachers take strike action extremely reluctantly,” said Ms Blower. “But we have been brought to this point by three years of below-inflation pay rises. People tell you teachers get long holidays, but a lot of young teachers are going to have to work the whole of summer because they simply cannot manage their debt and live on the money they get during the year.”

Ms Blower, 57, taught languages at some well-known secondaries in London, including Holland Park and Quintin Kynaston, before working for Hammersmith and Fulham council with children with behavioural difficulties.

In 1997, when she was NUT president, she made national headlines by pulling the elder of her two daughters out of Sats tests, in protest at the examinations.

She was elected deputy general secretary of the union in 2005, with a reputation for fiery rhetoric and a big collection of bonnets and wide-brimmed hats that saw her dubbed “the millinery tendency”.

She admits to playing a significant role in preparing this week’s action and continues to work from the deputy general secretary’s office, leaving Mr Sinnott’s undisturbed. The executive will next month set a schedule for elections for a new general secretary.

Ms Blower would not say whether she would run, but her leadership of the pay campaign can only enhance her profile should she choose to seek the job.

She does not yet have the cordial relationship with Gordon Brown that Mr Sinnott developed, and has acknowledged “fundamental” disagreements with ministers over pay, testing, academies and other issues.

“I worked very closely with Steve, whose leadership forged significant unity in the NUT, and who was really passionate about ensuring that teachers’ pay was not eroded,” she said. “The union is set on a course on which we agreed, and that has to some extent made taking the leadership in a difficult time easier than it would have been.”