Teachers leaders issue warning as nearly a fifth of Lancashire teens fail to make the grade at school.
Nearly a fifth of young adults in Lancashire reach 19 without a good pass in GCSEs or equivalent qualifications.
According to the Association of School and College Leaders disadvantaged students are hardest hit by the Government shifting its focus to GCSEs and A-levels over vocational qualifications.
Department for Education data collated by PA Radar reveals that 9,898 19-year-olds in Lancashire had achieved a level 2 qualification by the end of the 2018-19 academic year.
Level 2 qualifications are five or more GCSEs at grades A*-C, or 9-4, or the equivalents such as apprenticeships, NVQs and diplomas.
It means 82 per cent of young people in the area had level 2 qualifications – the same percentage as the previous year, and matching the national average.
Across England, in 2018-19 level 2 attainment dropped for the fourth consecutive year from a high of 86 per cent in 2014-15.
However, the same DfE figures show 59 per cent of the 2018-19 cohort in Lancashire achieved a level 3 qualification – two or more A-levels or the equivalents, such as a higher education diplomas or advanced apprenticeships.
That put the area above the national average for level 3 attainment, which fell to a six year low of 57 per cent last year.
Geoff Barton, general secretary of the ASCL, said: "The fall in attainment is caused by the Government’s decision to downgrade the importance of some vocational qualifications and AS-levels, and to place a greater focus on GCSEs and A-levels.
"This is a great shame as vocational qualifications and AS-levels serve many students very well, particularly those who face the greatest challenges and often come from disadvantaged backgrounds.
"Unsurprisingly, this process has therefore resulted in a widening of the attainment gap between the most and least deprived."
Mr Barton added that more needs to be done to support young people, including setting out qualifications "which suit different learners".
A spokesman for the DfE said the national figures represented an increase compared to 2009-10.
He added: "We have made good progress raising the standard of education and training on offer for young people.
"We are taking bold steps to further boost the quality of vocational and technical education to ensure those qualifications give students the skills they need for further study or to get a job.
"New, world class T-levels, to be launched in September, will help more young people acquire the skills they need to fulfil their potential."
The gap between those living in the most and least deprived areas of the country also widened to 18 per cent last year – the largest in eight years.
The figures include 19-year-olds who were in mainstream state schools.