New courses to turn teaching into a masters-level profession have been delayed by up to six months amid fears that a September start date was rushed and risked undermining the quality of the qualification.
The masters in teaching and learning will now begin in 2010 to allow more time to ensure it is up to scratch.
Ed Balls, the Schools Secretary, said the decision had been made after talks with the Teaching and Development Agency for Schools (TDA), which is responsible for the quality of teacher training.
"In order that we can be confident we are not going to compromise quality, it is better to take some more time," Mr Balls said.
The first wave of the qualification was supposed to be available to all new teachers starting work in the North West this September.
From January 2010, it was to be extended to all newly qualified teachers working in challenging secondary schools, including National Challenge schools where fewer than 30 per cent of pupils meet the core GCSE benchmark.
Now there will be no registration for the courses until January 2010 and teaching will not begin until "a few months" after that, Mr Balls said at the annual conference of the Association of Teachers and Lecturers (ATL) in Liverpool this week.
As reported in The TES last month, there had been widespread concerns that the qualification was being rushed through.
Universities responsible for running the courses said they were worried there had been insufficient information about funding and student numbers.
Bids to run the courses in some parts of the country also had to be re-submitted, raising further concerns.
Although the TDA had defended the scheme, it admitted the timescale was proving "challenging".
Mary Bousted, the ATL's general secretary, said she was delighted by the postponement. "A rushed implementation would have been disastrous," she said.
"We are sure that all concerned with this qualification will welcome the extra time.
"Usually it takes years for providers to develop a course as radically new as this, but they were being asked to do it in weeks.
"We still have concerns relating to the capacity of schools to provide the appropriate mentoring and whether the course will add unduly to the pressure on new teachers."
John Dunford, general secretary of the Association of School and College Leaders, also welcomed the postponement.
"It is more important that the masters is of high quality than it is introduced quickly," he said.
The TDA said it would still "actively promote" the course.
"Ministers believe it should be given the best opportunity to work well," a spokesman said, "so a short delay to early next year seems to be a sensible option."