Mr Blunkett won a standing ovation from more than half his audience at the National Union of Teachers' annual conference in Harrogate, and silence from the rest, after a fighting speech in which he attacked union militants.
Delegates voted at the weekend to take on a Labour government over class size, grammar schools and league tables. And they agreed to strike if a Labour government failed to reduce class sizes for all pupils.
Mr Blunkett said: "We won't tolerate division or bullying or threats, not simply from those who attend union conferences but from anyone who has a vested interest in any part of our country. However important they think they are, they will not stand in the way of myself and my colleagues radically changing the education system."
Outside the conference, Mr Blunkett said teachers should not strike over government policies whether on grammar schools, testing or inspection.
"I don't think withdrawing your labour and leaving children without a teacher assists in lifting standards or raising the esteem of teachers. As ever, withdrawal of labour should be a last resort."
He made it clear that he did not accept plans expected to be revealed in the Conservative manifesto today to ban teachers' strikes.
Mr Blunkett had been expected to receive a rough ride from the most militant delegates, but he was heard with barely a murmur as he backed traditional teaching methods, attacked teacher militancy and argued that low standards were the result of low expectations as well as economic disadvantage.
He was warmly applauded when he said that Labour would abolish the Government's nursery voucher scheme within one school term and would accept that class size mattered.
Labour's pledge to reduce class sizes for five- to seven-year-olds, he suggested, was the start of a process under which class sizes for older pupils might also be reduced. He said that they could trust him better than anyone to raise standards.
"I had to go to evening classes for six years to get A-levels and a business qualification to get into university.
"I taught in the heart of the South Yorkshire coal field where youngsters were bright, able and capable but written off by the system far too easily.
"When my own children went into an inner-city comprehensive with very low academic standards, I determined to liberate the children we represent from past dogmas and fights about the elite succeeding and the rest being written off."
Doug McAvoy, the union's general secretary, said they looked forward with optimism to a Labour government but warned that his members would be prepared to take industrial action if the needs of children and their teachers were not being met.
Gillian Shephard, the Secretary of State for Education, told BBC Radio 4's World At One, "If ... Labour were elected ... they would have to reap what they have sown over the years as far as education is concerned. What we heard at the NUT is the voice of the Labour Party."Reuse content