The number of primary schools failing to give pupils a good grounding in the three Rs has halved in the space of a year, official figures suggest.
In total, 521 schools in England are below the Government's floor target for primaries, according to an analysis of data used to create new primary school league tables. Last year, 1,310 schools were below the threshold.
The results show that schools have "responded to the challenge" that was given to them, the Department for Education (DfE) said. The latest tables show how more than 15,000 primary schools performed in national curriculum tests - known as SATs - in English (reading and writing) and maths.
Under the Government's current target, schools are considered failing if fewer than 60% of 11-year-olds reach the expected standard - Level 4 - in English and maths SATs tests, and fewer youngsters make two levels of progress in these subjects than the national average.
The national average for English progress this year is 92%, and for maths it is 90%. Schools that fail to reach this threshold are at risk of being closed and turned into academies. The latest figures show that of the 521 schools which are below the bar, 45 have already closed, with 37 becoming academies.
The rise in performance this year could be partly down to the Government's decision to scrap the externally-marked writing part of the English SATs test. Traditionally, marks for the test were lower than for the reading and maths papers. This year, for the first time, schools were given the option to mark the writing paper themselves, or to send it to an external marker.
A DfE spokesman said that the aim of their floor target was to boost standards and "end years of chronic under-performance", adding: "Today's figures demonstrate that schools have responded to the challenge. The floor standards we introduced were tougher and have improved performance. Heads, teachers and pupils deserve credit for meeting the challenge head on."
This year's top school, for the second year running, was Newton Farm Nursery, Infant and Junior in Harrow. It gained the highest average points score at 34.1. Second was Grinling Gibbons Primary School in Deptford, south east London.
The most improved school was Thornhill Primary School in Southampton, which saw results rise from 24% reaching Level 4 in English and maths in 2009, to 88% achieving it this year.
At the other end of the scale, among schools with more than 30 pupils eligible for the tests, was Ladygrove Primary School in Telford, which had 85% of students reaching Level 4 in English, but recorded no results for maths. Vane Road Primary in Newton Aycliffe, County Durham, which had 60 eligible pupils, recorded 0% for both English and maths.