Under proposals announced this week, primary teachers will be free to ignore the national syllabuses for geography, history, design and technology, music, art and PE.
They must however "have regard to" these subjects and should maintain a broad and balanced curriculum. No subjects would be dumped, Education Secretary David Blunkett said .
The planned cut has delighted teaching unions who have long said that the primary curriculum is overloaded. The National Association of Schoolmasters Union of Women Teachers described it as "the best news that primary school teachers have had since the new Government came to power".
The Government hopes the decision will make room for the daily literacy and numeracy hours it has recommended and which it sees as central to raising standards.
Schools could also broaden the curriculum in other directions and might, for example, introduce foreign language teaching.
The scheme breaks Sir Ron Dearing's ban on curriculum change. But it will be optional and schools may choose not to alter their teaching.
Announcing the plans, Mr Blunkett said the current curriculum was hampering progress. "Many primary teachers have been prevented from giving literacy and numeracy the attention they deserve," he said, "because the national curriculum has lacked the very clear focus on the basics which is crucial".
The Qualifications and Curriculum Authority south of the border will seek the views of schools and local authorities on the changes until March. If, as seems probable, the plans are formally adopted, it will publish advice on what "having regard to" means in practice: the essential points of each primary subject.
Chief executive Dr Nicholas Tate said this week that the QCA has already devised lists of core elements which take up no more than one page of A4 per subject.
In fact, he said, the planned relaxation pointed towards the changes he is likely to introduce as part of the QCA's major curriculum overhaul in 2000.
The Government's proposals follow a model backed by the National Union of Teachers. This also won the support of heads and governors .
In a letter to Mr Blunkett, chief inspector Chris Woodhead gave the initiative a "whole-hearted welcome" and said that his inspectors would not criticise schools for concentrating on maths and reading.
But the news has also caused some alarm. Liberal Democrat spokesman Don Foster said: "The Government has announced an overhasty, unplanned retreat which could create chaos in our classrooms with teachers and teacher-trainers uncertain about what they should now do."
Subject groups such as the Historical Association are also concerned. Sue Bennett, an executive member, said she feared a narrowing of the curriculum.
The Geographical Association received the news "with a sense of incredulity and outrage". It is also thought to have angered many within the QCA although they have managed to fend off calls for a still more basic syllabus.
Mr Blunkett's announcement appears to pre-empt the QCA's own, substantial review of the whole national curriculum. The Welsh Office is considering alternative proposals for a slimmed-down curriculum.