More than a quarter of people in some pockets of the UK have no qualifications at all, according to research by the University and College Union (UCU).
The analysis paints a picture of a country "divided into educational haves and have-nots", with the areas of lowest educational attainment being found in the Midlands, the North and Scotland.
While Glasgow North East has the highest proportion of unqualified residents (27.5 per cent), the Midlands constituencies of Birmingham Hodge Hill (27.2 per cent) and Wolverhampton North East (25.6 per cent) are close behind.
Among the other worst-performing areas are Preston, Bradford East and the Liverpool constituencies of Walton and West Derby.
In total, 96 of the 632 parliamentary constituencies in England, Scotland and Wales - more than one in seven - have 15 per cent or more residents with no qualifications.
Of the 50 constituencies with the highest percentage of people with at least one qualification, 44 are in the South of England. The places with the fewest unskilled workers are Buckingham (2.2 per cent); Devizes in Wiltshire (2.4 per cent); and Worthing West in West Sussex (2.8 per cent).
The UCU blamed the figures on the increase in the cost of education and cuts to financial support in recent years.
"This research shows that access to the benefits that education brings is heavily rationed in Britain today, with some constituencies having almost 13 times more people without qualifications than others," UCU general secretary Sally Hunt said.
"It is unacceptable that there is such widespread under-achievement in Britain today. We live in a fast-changing knowledge economy where education is key to employment and getting on.
"Yet politicians all too often seem to see cutting off access to educational opportunities as an easy target. Given the opportunity, everyone can benefit from education."
David Hughes, chief executive of adult learning body Niace, said the areas with more unqualified people tended to be in more deprived parts of the country.
"It reflects the fact that the education system is still loaded towards the family you are brought up in," he said.
"Economic class is still the biggest determinant of educational achievement; if you are brought up in a house full of books, your chances are better than if you don't have access to them."
Mr Hughes added that free training for improving adult literacy, language and numeracy skills was still available through the Skills for Life programme.
He also called for schools to invest pupil premium funding in family learning, in which parents also receive training to help them get involved in their child's education. "We think this could bring real benefits," he said.