The Abbott government has pledged to deal with the overcrowding of the curriculum as a "matter of priority", saying it would look carefully at when and how subjects were introduced to children.

Overcrowding in the curriculum was the main issue of concern raised by principals, teachers and parents during the review conducted by education consultant Kevin Donnelly and academic Ken Wiltshire.

The review received almost 1600 public submissions and held consultations with 72 organisations and eight individuals.

"Overcrowding means that teachers are finding it difficult to implement the Australian curriculum and cover all the content in each subject," the Australian government said in its response to the review.

"It also means that students are not necessarily getting the right amount of time devoted to the content in each subject that they really need - for example, literacy and numeracy in the early years of primary schooling."

The review suggested there should be a greater emphasis on phonics (where children learn new words by sounding them out) in the English curriculum, particularly in the early years of reading.

It warned the primary science curriculum was sacrificing depth for breadth, pointing out that in Singapore and Finland - two of the most high-performing education systems in the world - science was not taught until years 3 and 5 respectively.

The review said the geography curriculum should focus more on physical geography (the study of the natural environment) and less on studying human activities.

The controversial "cross-curriculum priorities", which required sustainability, Australia's engagement with Asia, and Aboriginal and Torres Strait Islander histories and cultures to be "embedded" in every subject, also came under fire.

"There is concern about the seemingly political determination of these three "priorities" ... and a fear that changes of political persuasion could lead to constant changes in the priorities," the report said.

Science and maths teachers had questioned whether it was appropriate to teach themes such as "engagement with Asia" within their disciplines.

The review also questioned whether the curriculum was balanced.

"The review received a significant number of submissions arguing that the Australian curriculum did not pay enough attention to the impact of Western civilisation and Judeo-Christianity on Australia's development, institutions and broader society and culture," it said.

Although these concerns were predominantly raised in relation to history and civics and citizenship, they also cropped up in arts, English, economics and business.

Inquiry-based learning, where students work on projects related to their area of interest, was privileged in the geography, history and science curriculums according to the review.

"Such an approach is often associated with constructivism and a focus on skills and capabilities at the expense of essential knowledge and the need for explicit teaching of which direct instruction is one example," the review said.

The reviewers said they were not saying there was no place for inquiry-based learning but that caution should be exercised to ensure it did not become the prevailing orthodoxy.

Government responds to review findings

Education Minister Christopher Pyne said Australia's educational performance would fall behind unless most of the review's recommendations are adopted.

"The review doesn't find that we face any kind of crisis in education but the review says that we could do better and this is a way of moving forward," he said on Sunday.

"From my own knowledge over the last few years as a minister and shadow minister, it's clear that that edge that Australia's always had in terms of high quality school education does not exist any more against our Asian competitors and if we want our children to be international in their outlook and travel the world and be able to compete for jobs with everyone then we are going to have to adopt a lot of this review if we want our curriculum to be the best it can be."

Mr Pyne said he believed there would be strong support in the general community and among state and territory governments for the review's findings. He acknowledged he would have to work closely with the states - which own and operate schools - to implement the recommendations.

"I think the states and territories will believe this is a step forward in a positive direction," he said. "So I would like to see most of it adopted. There's nothing in it that I can see that the States and territories would baulked because nothing is trying to drive a political agenda.

"I don't get the sense that this is an ideological document and I don't feel the national curriculum is an ideological document."

Mr Pyne said he backed the review's finding that the national curriculum had tried to squeeze the three "cross-curriculum priorities" - Aboriginal and Torres Strait Islander history and culture; sustainability; and relations with Asia - into subject areas they did not belong. It is probably not appropriate to integrate relations with Asia into mathematics or physics lessons, he said.

- with Matthew Knott