Just one in five primary heads believes the new curriculum will have an impact on their schools if the existing testing regime stays in place.
A straw poll carried out by The TES and teaching union the NAHT found that only 20 per cent believe the overhaul will make a difference to their schools while the key stage 2 Sats are still administered to their final-year pupils.
Sir Jim Rose, education adviser, has proposed that the current subject-based curriculum should be replaced by one based on six areas of learning. The changes aim to give teachers more freedom to design lessons to suit the needs and interests of their pupils.
Ian Foster, assistant secretary of the NAHT, said: "We remain unconvinced that his proposals will be taken up wholeheartedly. With the best will in the world, while tests remain, heads feel they need to get the best possible performance in those areas that are tested. That undermines the idea of a broad curriculum. The freedom is illusory."
Other findings from the poll of 60 heads and deputies found that 70 per cent said they entirely or mostly agreed with the changes proposed by Sir Jim. However, this is perhaps not surprising as more than 40 per cent said the new national curriculum was a fair match to how they already worked.
The poll also found that only 18 per cent of heads said the prospect of a Conservative victory was delaying their preparation, despite the party being open about its plans to scrap the reforms.
One Surrey primary head said: "The Conservatives won't make much difference, too much effort has gone into it. This is a curriculum that has come from the professionals, rather than the politicians."
Analysis, pages 32-35.