The proportion of students commencing UK university courses who had attended state schools fell again in 2004-05, latest figures show.
Fewer students have applied for courses starting this autumn
The percentage starting full-time first degrees was 86.7%, down from 86.8% the year before, when it was also down.
The percentage from poorer homes also went down. Ministers described the figures as "disappointing".
Applications for courses starting this autumn - when fees go up - are down by 3.5%, after a record rise last year.
National Union of Students vice-president Wes Streeting said the number of students in higher education from lower socio-economic groups remained low.
Only 28.2% of young first-year degree students starting courses in 2004-05 came from lower socio-economic groups, down from 28.6%, the Higher Education Statistics Agency (Hesa) figures showed.
"This is deeply worrying given that we have not yet seen the impact that top-up fees will have on these groups, who, as many surveys have shown, are the most likely to be put off university by fears of debt."
Higher Education Minister Bill Rammell said ministers were also disappointed.
"The government is determined to do everything possible to make further progress and widen participation."
Outreach activities were already making a difference, he said, and improvements would appear "in future years".
"There remains an economic need for more graduates, and to achieve this we need a more representative student population."
Hesa maintains projections each year for the eventual number it expects not to complete their studies.
It has raised this dropout rate from 14.4% to 14.9%.
The Independent Schools Council criticised the use of state school education as a "performance indicator".
General secretary Jonathan Shephard said that, as a measure of social inclusion, it was "meaningless and misleading".
Nearly a third of children in its member schools received help with fees and hundreds of thousands of families lived in postcodes with average or below average incomes, he said.
The separate Universities and Colleges Admissions Service (Ucas) figures showing a fall in applications to full-time degree courses had been expected in the context of a record increase of 8.2% last year.
By the end of June, 469,731 students had applied for courses starting in the autumn, compared with 486,915 at the same point last year.
More than 55% were women.
The number of applicants from EU countries outside the UK rose 3.7% to 27,817 - despite 1,059 fewer applications from the Republic of Ireland (a decline of 14.7%).
But the number of potential undergraduates from non-EU countries was down 8.8% to 40,686, with China, Nigeria, Malaysia, Pakistan, South Korea, Kenya, Japan and Zimbabwe all showing more than a 10% decline.
Applications for places on mathematics courses saw a rise of 11.6%.
Chemistry applications were up by 4.4%, chemical process and energy engineering applications by 7.9%, engineering applications by 4.9% and medical, biological and agricultural science by 4.3%.
Liberal Democrat Shadow Education Secretary, Sarah Teather MP said: "There's no hiding from the impact of top-up fees: they deter young people from going to university.
"The government doesn't seem to be taking the long-term consequences of their tuition fees policy seriously."
But Mr Rammell said: "I am confident that we will continue to see a return to a long term upward trend, as happened after tuition fees were introduced in 1998."
The Education Secretary, Alan Johnson, told the Commons education select committee the government was committed to "a very meaningful review" of the impact of top-up fees in 2009 - after the next election.
"The review could lead to us abandoning this policy altogether. It could be damaging."
A spokesman for the vice-chancellors' group, Universities UK, said the Hesa figures should be seen in context.
"If we are to continue to widen access from disadvantaged groups, it is vital that we increase the staying on rates beyond compulsory schooling," he said.
Internationally the UK still had one of lowest dropout rates.
Shadow higher education minister Boris Johnson said the figures were "not completely discouraging".
The number of both young and mature part-time entrants from low participation neighbourhoods had increased as had the number of mature full-time students.
"However, these figures do indicate how much work there is still to be done."