Just one in seven children at Key Stage 2 from the Gypsy and Roma communities in Britain can read and write, a new race survey has shown.
This compares with 71% of Chinese children – the best performers in the country – between the ages of seven and 11 who meet the expected standards, and 54% of white British pupils.
The shocking gaps in attainment between children of different ethnicities were outlined on Tuesday (10 October) as the government prepares to launch its national survey into race inequality.
The Ethnicity Facts and Figures website, which will go online at midday, will allow the public to examine how life in Britain differs for people of different racial backgrounds.
It covers 130 separate areas – including health, education, employment and the criminal justice system – and draws on statistics from all government departments as well as previously unpublished data.
The website, said by Number 10 to be the first of its kind in the world, was commissioned by Theresa May shortly after taking office.
She will say alongside the launch how it will be used to challenge society and public services to "explain or change" disparities.
She says the audit will become an "essential resource in the battle to defeat ethnic injustice" which must be confronted at all levels of society – from central government to local communities.
Among the key findings were that the 8% unemployment rate for black, Asian and minority ethnic people is nearly twice that of white British adults.
White people, Indians and Pakistanis are also more likely to own their own homes than those from the Bangladeshi and black communities.
In education, Chinese and Asian secondary school pupils outperform white and black children, particularly those eligible for free school meals. Gypsy, Roma and Traveller children do significantly worse, figures show.
An external review will also now look at cases of children excluded from school after statistics revealed pupils from certain ethnic groups were more likely to be banned from the classroom.
In 2015/16, Irish traveller pupils were the most likely to be excluded, with a rate of 0.49%. They were followed by Gypsy and Roma children (0.33%). Black Caribbean pupils – at a rate of 0.29% – were permanently excluded at three times the rate of white British pupils.
Ethnic minorities were also found to be under-represented at senior levels across the public sector.
The government's new website goes online the same day a new report warns that years of Conservative-led austerity has had a devastating impact on black and minority ethnic (BME) women and households.
The poorest black and Asian families are set to suffer a 20% drop in living standards by 2020 as a result of benefit changes and cuts to services since 2010, the report says.
Jointly published by the Runnymede Trust and the Women's Budget Group, the authors say it gives a stark insight into how "austerity is hitting the poorest hardest, women are losing more than men and BME households are losing more than white households".
Launching the government's own audit website into racial inequality, the Prime Minister is expected to say later on Tuesday: "People who have lived with discrimination don't need a government audit to make them aware of the scale of the challenge.
"But this audit means that for society as a whole – for government, for our public services – there is nowhere to hide. These issues are now out in the open. And the message is very simple: if these disparities cannot be explained then they must be changed.
"Britain has come a long way in my lifetime in spreading equality and opportunity. But the data we are publishing today will provide the definitive evidence of how far we must still go in order to truly build a country that works for everyone."
Welcoming publication of the audit was director of Operation Black Vote Simon Woolley.
He said: "The findings from the Race Disparity Audit presents us with a real opportunity to make transformative change in tackling persistent race inequality. Yes, some findings make uncomfortable reading, but unless these things are laid bare we can't begin to resolve them.
"Over many years the Prime Minister has shown a real desire to grapple with the scourge of racism including confronting high levels of BAME Stop and Search, BAME deaths in police custody and now this."