Lee Elliot Major, professor of social mobility at the University of Exeter, said competition to get into top sixth forms “will be fiercer than ever”, adding that fears over VAT being added to private school fees may drive more families to seek out places in the state sector.

But Paul Whiteman, general secretary of the NAHT school leaders’ union, said there was a “wide range” of other options for teenagers, such as school sixth forms and further education colleges.

About 170,000 students are due to get results for BTec Tech Awards, BTec Firsts and BTec Level 2 Technical courses, while about 110,000 will receive results for Cambridge Nationals.

The pass rate for National 5, Higher and Advanced Higher exams in Scotland rose across the board this month.

Top A-level results rose again last week – with 28.3% of all grades across England, Wales and Northern Ireland marked at A* or A.