The results for 11 year olds show an overall improvement
Schools Minister Jim Knight says he has confidence in England's Sats results, despite the embarrassing problems with the return of this year's papers.
The tests taken by 11-year-olds show a slight improvement - and Mr Knight says the sample size, in excess of 90%, makes them statistically reliable.
About 5,000 test papers from about 460 primary schools have not been returned.
Teachers' unions have been divided between those doubting and those defending the robustness of results.
The Qualifications and Curriculum Authority says that the unreturned test papers have all now been marked - and it expects these missing marks to be given to schools by the end of the week.
The schools minister said he was having daily discussions about the test marking delays.
SATS RESULTS 2008
English up 1% to 81%
Maths up 1% to 78%
Science stays at 88%
72% reach expected level at English and maths
61% reach expected level at reading, writing and maths
12% achieve highest grade, Level 5, in all subjects
36% of girls reach Level 5 English
23% of boys reach Level 5 English
460 schools waiting for results
But he emphasised that difficulties with delivery did not undermine the validity of the results - that these were separate issues.
"The problems have been difficult, we've all heard the reactions of head teachers, and we've heard the apologies from the QCA and their contractor, and they've acknowledged the reputational damage.
"But it still remains the case that Ofqual are advising us that the quality of marking is as good as it's been in previous years.
"There are always reviews and appeals, that happens every year. I have confidence in these figures that we are putting out today."
The overall improvement in English and maths results, continuing an upward trend, was welcomed by the minister.
"Compared to 1997, 101,000 more 11-year-olds are now achieving the target level for their age in English and 93,000 more in maths," said Mr Knight.
But looking into the detail of the results, he highlighted two areas of concern - the lack of progress in writing and the fall in pupils achieving the highest grade of Level 5.
Jim Knight said he had confidence in the reliability of the test results
For the writing element of English, only 67% reached the expected level, which Mr Knight said was "a concern, particularly among boys" - only 60% of whom attained that level.
Writing would be a focus for improvement in the autumn, with an Every Child a Writer programme, individual tuition and planned changes in teaching techniques, he said.
He also spoke of the "concern and disappointment" at a downturn in those high-flyers achieving Level 5 in all three subjects, which he said suggested a greater need for more personalised lessons to stretch the more able.
This drop in the top grades was labelled as the "most worrying feature" of the results by the Shadow Schools Minister Nick Gibb.
"These are alarming figures, suggesting that fewer pupils are achieving excellence, and that pupils are not being stretched to the best of their abilities," said Mr Gibb.
The Liberal Democrats' children's spokeswoman, Annette Brooke, highlighted the unresolved problems with this year's marking.
"The shambles surrounding the marking of this year's tests are a disgrace: 460 schools still do not have results for all of their pupils," she said.
There were sharp differences within the teaching profession over the publication of the primary school test results.
The National Association of Head Teachers had already warned that it "beggars belief" that the government was pressing ahead with issuing the results.
However the head of the NASUWT teachers' union, Chris Keates, said the results should be "celebrated" - and labelled critics as "obsessive opponents of the tests".
"This year, as every year, the results are based on a statistically robust sample. Any claims that not all the results are available and, therefore, they should not be published should be dismissed as ill-informed nonsense.
"I have no doubt, however, that the serial detractors who rush every year to criticise the outcome of the tests will once again be much in evidence."
John Bangs from the National Union of Teachers said that "instead of publishing the results, the Government should have taken the opportunity to ask Lord Sutherland to conduct a fundamental review of the entire, flawed testing system".
Mary Bousted, head of the Association of Teachers and Lecturers, said that "criticising the publishing of the Sats results shows a lack of understanding of statistical theory. With almost complete returns, the results are reliable at a national level.
"This doesn't say much, however, as the reliability of the test results has always been too low to provide accurate comparisons between schools."