The scale of an education crisis among Protestant working class children in Belfast was today exposed by a powerful Parliamentary body.
And the findings of the Commons Public Accounts Committee (PAC) were swiftly cited by Secretary of State Peter Hain to push the case for major schools reform in Northern Ireland.
In their new report, the MPs rapped faltering efforts to tackle the problem of poor maths and English skills among many pupils across both communities.
But they voiced particular alarm about levels of educational achievement within deprived Protestant areas of Belfast.
The PAC concluded that the issue must be "one of the major challenges" facing Northern Ireland.
It said "significant differences" existed in the GCSE English and Maths results of Protestant and Catholic schools in poorer parts of the city, with Protestant pupils performing "disturbingly less well".
The MPs also noted that social deprivation levels are higher in Catholic areas.
As part of their investigation, the PAC examined statistics for Glasgow schools and found no marked differences between Catholic and non-denominational schools there.
In addition, Protestant children in deprived Belfast districts were found to be doing "much less well" than their counterparts in non-denominational Glasgow schools.
The committee was particularly shocked that only 4.4% of Protestant children who sat GCSE Maths in secondary schools in disadvantaged Belfast areas had achieved grades between A* and C2.
It was also heavily critical of the disappointing returns from a £40m drive to raise numeracy and literacy standards across the province's schools system.
It said progress had been "manifestly unsatisfactory" and the Department of Education had "failed to show sufficient leadership in driving things forward".
PAC chairman Conservative MP Edward Leigh said today that, although the committee recognised the achievements of many children in the province compared favourably with the brightest in the rest of the UK, the school system in Ulster had tolerated, for too long, a situation where a significant proportion of children were underachieving.
The Secretary of State today told the Belfast Telegraph: "This is a very serious and important report from the PAC and we must consider it carefully and provide a full response in due course.
"However, it does appear to vividly demonstrate the point that I have been seeking to make over many months, that while Northern Ireland's education system does very well for some pupils, too many are being failed by it.
"The setting of a young person's life chances by a couple of exams cannot be the right way to proceed and that's why ending the 11-plus is so crucial."
Mr Hain said "far more" than abolishing the 11-plus was required and highlighted other current education initiatives including investment in before and after school activities.
"Northern Ireland can and should be world class, but it can only thrive in a harsh global climate if we don't waste the talent of any of our young people," he said.
In its evidence to the PAC, the department suggested that the "considerable time" devoted in P6 and P7 to preparing for the 11-plus was "narrowing" the curriculum and having a negative effect on the 60% of pupils who do not go to grammar schools.
The PAC, meanwhile, cautioned against "a simplistic view" that "structural change" was the answer to the problems.
"The differences which we have highlighted between Catholic and Protestant children in socially deprived areas suggest that there are much more profound difficulties at work than the system of selection," it said.
The Commons report was today welcomed by Ulster peer Baroness Blood who has had a long association with skills training in Belfast's Shankill area.
Baroness Blood said education had been undervalued historically in Protestant working class areas. She also stated that some "tremendous work" was currently being done but more was needed and funding had to be better targeted.
"We still have a huge problem in numeracy and literacy, there's no doubt about that," she said.