The poll of more than 500 primary heads, commissioned by the Centre for British Teachers, builds on last year's survey which also showed strong support.
It discloses that:
* 96 per cent backed the literacy strategy and more than three-quarters believe it has raised standards in reading and writing since it was introduced in 1998.
* 98 per cent supported the numeracy hour brought in a year later. Just over 90 per cent said the strategy had improved the quality of maths teaching and a similar proportion said they were confident it would raise standards.
* More than 80 per cent of heads believed teachers' confidence in maths and English had increased.
* About 90 per cent of heads said pupils and parents were also positive about the initiatives.
* 60 per cent thought the literacy strategy had helped raise pupil achievement in other subjects.
* The vast majority of heads thought the maths booster programme was helping to raise standards.
Stephen Anwyll, director of the literacy strategy, said: "It is testimon to the commitment and hard work which headteachers, teachers and support staff have demonstrated in establishing the literacy hour and in making such good use of the training materials and resources."
Tim Coulson, director of the numeracy strategy, said that, as the initiative became embedded, even more heads had expressed their commitment to it.
"Schools have not only used materials and funding made available at the beginning, but have also more recently taken up the opportunities provided to support children who are not keeping up with the rest of the class," he said.
Year-on-year improvements in key stage 2 national test results have been put down to the success of the literacy and numeracy hours.
The Centre for British Teachers provides management and professional support services for both strategies.
Education Secretary David Blunkett welcomed the survey results and claimed that they demonstrated that headteachers had been won over to the Government's standard-raising agenda.
"The poll shows how far we have moved in just three years and illustrates the extent of the transformation in attitudes among teachers and heads," he said.