In possibly the first known incidence of teenagers listening to politicians, it appears that 16-year-olds are rapidly abandoning the study of English. The three types of English A-level have seen their numbers decline by one-fifth over the past three years, with sciences up by the same amount.

Faced with the constant message from the government that science, technology, engineering and maths are everything, teens are opting for these subjects at A-level and university. It started with Nicky Morgan, who, as education secretary, made a speech in autumn 2014 urging young people to study science. “[In the past] if you didn’t know what you wanted to do … the arts and humanities were what you chose because they were useful … We now know this couldn’t be further from the truth. The subjects to keep young people’s options open are Stem subjects.”

In the distance one could hear applause from the heavily funded lobbying organisations for these industries. But no one was shouting – as they should have been – “Where will we find our English teachers?”

The situation for English is also worsening as students are pushed further from the subject. Sixth-formers are told that, faced with sky-high university fees, they need a return on their investment, and so are eschewing Shakespeare in favour of “vocational” degrees in law, or medicine, or business. A recent intern I worked with, Eve Debbage, who is studying English at UCL, says many people told her that she wouldn’t get a job if she took the course.

Debbage says: “You’re encouraged to take A-level subjects that are similar to each other so you improve the chance of excelling come results day.” Taking maths and English together was seen as “nonsensical”. And humanities? “A risky choice for students in such an economically insecure period as Brexit.”

A baby bulge is hitting secondary schools, and more teachers are needed. Particularly in core subjects – like English

One of her friends noted that English was seen as “too risky” given examiner subjectivity. “If you learn the stuff for science and maths, it’s less luck of the draw – unlike English where a dodgy question could destroy your chances at getting into your first-choice university.”

All this should prompt questions about the whole A-level system in England. The government has issued plans to cut International Baccalaureate funding entirely for state schools. But this system, which requires everyone to study maths, English and a foreign language up to the age of 18 (along with other optional subjects) has been gaining popularity among those who have studied the sector, and calls for a move in this direction have been growing – most recently from Conservative MP Robert Halfon, who heads parliament’s education committee.

The promises of great science jobs are not necessarily fulfilled, by the way. Computer science courses persistently have the highest unemployment rates. Meanwhile, English graduates still go into a wide variety of careers, from publishing to the civil service. And soft skills are always in demand. Google cites communication skills and creativity among its top prerequisites for employees.

At the same time, the shortage of teachers is getting worse. There will be a demographic squeeze in the next few years, as a smaller group of 18- and 19-year-olds go to university. If one-fifth fewer have studied English to A-level, the pool of potential English teachers has also just diminished by a sizeable wedge. A baby bulge is hitting secondary schools, and 50,000 more teachers are needed. Particularly in core subjects – like English. We need to recruit a lot of English teachers over the next decade.

Ultimately, it’s daft to pit maths against English. A rounded education would involve both. It’s time to get over the “either/or” mentality and allow students to study what they love, even if it’s maths and economics with English literature.

• Laura McInerney is chief executive of Teacher Tapp