By Gary Eason
BBC News education correspondent
Attainment in English and maths is key to secondary school performance
White boys from poorer homes now do worse in primary school tests in England than any other main group, latest figures show.
Only 48% of white British boys eligible for free school meals achieved the expected level in English and maths.
The average for all pupils was 71.8% - and that gap, 23.8 percentage points, was up from 23.1 points last year.
Attainment varied between ethnic groups with Chinese, Irish, Indian and mixed white and Asian children doing best.
It was known already that nationally, attainment in both English and maths in the Key Stage 2 national curriculum tests - commonly known as "Sats" - had fallen this year.
This new breakdown of the provisional data by various pupil characteristics, published by the Department for Children, Schools and Families, reveals the detail behind the headline.
Last year 52.5% of white British boys and girls together had the worst performance, though the girls' attainment was 55.4%.
This year, as a group, white British pupils again did worst.
Again it was the boys' performance that was weaker than the girls'. While 55% of girls achieved the expected level they were outperformed by the next nearest group - Pakistani girls (57.4%).
By far the worst performance was among travellers of Irish heritage and those of Gypsy/Roma background - only about one in five of whom did as well as they should.
LEVEL 4 ENGLISH AND MATHS, FREE SCHOOL MEALS
All pupils: 53.3%
White British boys: 48%
Black Caribbean boys: 49.7%
Asian boys: 58.7%
White British girls: 55%
Pakistani girls: 57.4%
But there are only a few hundred of them in the whole country.
There are almost 200,000 white British boys, of whom 31,237 (16%) were from homes poor enough to qualify them for free school meals.
In the past, poor black boys have tended to have the weakest performance.
But this year 51.6% of black boys on free meals made the grade and the gap in their attainment compared with the national average, 20.2, was down from 21.8 in 2008.
Attainment was 49.7% among the weakest group of black boys, those from Caribbean backgrounds.
This left the white British boys on free school meals at the bottom. Even worse for the government is the fact that the attainment gap widened.
This has been a persistent problem for ministers.
Research shows that even children from affluent families who started out in the bottom ability group as toddlers overtake those from the poorest backgrounds who started out in the top ability group, by the time they are six or seven.
'No child should fall behind'
Schools Minister Vernon Coaker said of the overall results: "Let's face facts - primary school standards have been transformed over the last 12 years with 98,000 more 11-year-olds now reaching expected levels in English and maths regardless of their backgrounds.
"No-one would want to turn the clock back."
He said no child should fall behind at school and the government knew there was still more to do - which is why it had set out a comprehensive programme to close historic attainment gaps further.
"We're giving up to 600,000 seven to 15-year-olds one-to-one tuition from this term if they are falling behind in English and maths.
"And we are expanding the intensive 'Every Child early intervention programmes', for six-year-olds most at risk of falling behind in reading, writing and maths so they do not fall behind at the start of primary school."