With GCSE results day less than a week away, the anticipation and nervousness of teachers and students is building.

That’s nothing new. But this year, another question is weighing on people’s minds and adding to the unease. Are the country’s most privileged young people getting an easier ride through the system owing to GCSE reforms?

Speculation has returned that IGCSEs - a GCSE equivalent that is open to the independent sector but not state schools - are a less demanding option.

Critics argue that IGCSEs are not as tough as reformed GCSEs, cover less content and give private schools greater flexibility because they can include coursework components.

And Tes has found that some universities are asking for lower equivalent grades for IGCSEs under the A* to G grading system than they are for reformed GCSEs, which use 9-1.

The exam boards offering the IGCSE say that the criticism is unfounded, insisting that careful steps are taken to ensure that it is comparable to the GCSE. The private schools using IGCSEs, meanwhile, argue that they are rigorous qualifications, and even suggest that the attack on them may be motivated by prejudice against the fee-paying sector.

So who is right? And is our exam system the level playing field that it’s supposed to be?

“IGCSE” is trademarked by Cambridge Assessment - the “I” stands for “international” - but the term is often used as shorthand for a family of alternative key stage 4 qualifications provided by a number of exam boards (they are officially called “Level 1/2 certificates”).

Originating in the late 1980s, they were established as an overseas relative of the newly created GCSE because of the global standing of the British education system.

As concerns began to mount at the turn of the 21st century that GCSEs were becoming dumbed down, many private schools began switching to the IGCSE in the belief that it represented a more rigorous qualification.

But the great expansion of IGCSEs into the state sector came later, when Michael Gove was education secretary. The qualification helped to inspire his GCSE reforms and, in 2012, he encouraged state schools to think about the IGCSE as “an appropriate preparation for the changes that we hope to introduce”. To enable state schools to take them, IGCSEs were moved into the regulatory framework overseen by Ofqual.

However, the Department for Education then made a dramatic volte-face by removing IGCSEs from state school league tables in 2017, to ensure that there would be no opting out of its new reformed GCSEs.

With state schools effectively barred from taking IGCSEs but many private schools still using them, questions have re-emerged about the equity of the current system.

Even before GCSEs were reformed, concerns had been raised that some IGCSEs might be less challenging. In 2013, the number of candidates for IGCSEs in English language exploded from 18,000 to 78,000.

Brian Lightman, then general secretary of the Association of School and College Leaders, said schools were moving to the IGCSE because they thought it was “easier” and believed their students “were going to get higher grades than in GCSE”.

This might seem strange given that many private schools originally moved to the IGCSE because it was a more rigorous qualification, but the two things are not necessarily irreconcilable. One exam industry insider, speaking to Tes anonymously, said it was widely thought that IGCSEs offered greater stretch for the ablest candidates, while also being more accessible for pupils on the C/D border.

Questions over the comparability of the qualifications have become even more pressing since GCSEs were reformed. The government specifically redesigned GCSEs to be more challenging, and in some subjects the amount of content has increased. With no parallel process to make IGCSEs harder, some people believe the qualification has fallen behind the GCSE in terms of what is expected from candidates.

James Eldon, the principal of Manchester Enterprise Academy, has experience of both qualifications, having previously introduced the IGCSE in English when he was running another school in Manchester. “Because of its international status, it needed less cultural capital to understand and was designed for a much broader audience,” he says. The new GCSEs, however, are “fatter and broader, and require more knowledge”.

The new GCSEs are also designed to provide greater stretch at the top end. The best performers are covered by three grades, 7-9, rather than the two A or A* grades.

That need for more differentiation between the ablest candidates necessitates questions that are more difficult. So reformed exams also carry the risk of pupils sitting higher tier papers having their confidence - and, therefore, their performance - knocked by being unable to answer questions aimed at the highest-ability candidates.

Another difference between the qualifications is that schools opting for IGCSE are given the choice to take a fully exam-assessed course or a course that includes a coursework component. This contrasts sharply with the reformed GCSEs, which no longer include coursework in most subjects.

“Coursework is now seen as anathema - it’s a heresy almost,” says Eldon. Instead, candidates “have to take a load more exams in one fell swoop” - an experience that he says is more stressful for his pupils.

Another state school leader who thinks the IGCSE is less challenging than the reformed GCSE is Jon Ryder, deputy headteacher of Lord Williams’s School in Oxfordshire.

He says he was first alerted in the spring while talking to a student who was thinking about entering his sixth form. The student was taking the IGCSE offered by Pearson and was studying John Steinbeck’s novella Of Mice and Men - a text no longer on the reformed GCSE syllabus.

“The choice of texts is much more open, and texts that are regarded as being insufficiently demanding for regular GCSE are allowed on the IGCSE,” Ryder says.

Ryder agrees with Eldon that the option of doing coursework is an advantage to private schools. He also points out that in the IGCSE poetry assessment, the poems are available in an anthology on the students’ desks during the exam, whereas in the reformed GCSE, students are required to memorise them.

Ryder is not just concerned about the different experiences that state and private school pupils will have sitting the two qualifications. He also worries about how this will impact on students’ choices at A level and beyond.

“Our students have just found it a real grind,” he says. “It’s been a real slog to get through the GCSE course, with the learning of the poems, memorising quotes. It’s been a much less enjoyable experience, particularly for those who are less academic.”

Ryder fears that his students will be less willing to do English at A level and university, even though it’s a facilitating subject that offers access to “key positions of power and authority in society”.

Crucial to all of this is how universities treat IGCSEs. A glance at the admission requirements of the elite Russell Group universities shows that they generally view the IGCSE as equivalent to GCSE, which is a problem if the critics are correct and it is actually a less challenging qualification.

And there is potentially even greater scope for unfairness between private and state school students because of differences in the grading structure between the qualifications.

So is the IGCSE a softer qualification? The government does not appear to demur from this view. When asked why IGCSEs were removed from performance tables, a Department for Education spokeswoman says that they are no longer recognised because “they have not been through the same approval and quality control process as the new gold standard GCSEs”.

The exam boards that provide IGCSEs dispute the suggestion that they are an “easier” qualification. While they have not gone through the same reform process as GCSEs, the boards argue that these reforms just brought the GCSE closer to the IGCSE.

Michael O’Sullivan, chief executive of Cambridge Assessment International Education, tells Tes: “Cambridge IGCSE qualifications were a benchmark for the design of the reformed GCSE in England, and the content of reformed GCSE and Cambridge IGCSE syllabuses have extensive overlap.”

Cambridge says it pegs its IGCSEs to the GCSE by using “statistical evidence and comparability studies”. Similarly, a spokeswoman for Pearson says that the board has “processes in place to ensure that [the qualifications] are comparable to GCSEs”, including ensuring that the same committee members oversee the exam setting, marking and grading processes, with grade boundaries set to ensure comparability between the qualifications.

But “comparable” is an imprecise term. Just because you can compare two qualifications, it does not mean they are at the same level of difficulty. And if IGCSEs were marketed as broadly equivalent to GCSEs before the reforms, how can they be the same now without having undergone a parallel reform process?

However, the idea that students who take the reformed GCSEs will actually get worse grades because the exams have become tougher - while IGCSEs pupils are insulated - is questionable. That is because the “comparable outcomes” approach adopted by Ofqual ensures that the profile of the grades that pupils get will be broadly similar to pre-reform GCSE results.

For its own part, Ofqual cautions against making direct comparisons between the qualifications. A spokesman says: “IGCSEs are different qualifications to GCSEs, with different content and assessments. Therefore, it is not possible to make meaningful comparisons between the two.”

The suggestion that private schools might choose to do IGCSEs to game the system is one that Barnaby Lenon, chair of the Independent Schools Council and former head of Harrow School, says is “ludicrous”. “I know there are no heads sitting around saying, ‘Ha, ha, ha, we’re doing the easier exams.’ That is utter nonsense.”

On the contrary, he says, it would be highly damaging to private schools if they plumped for a qualification that they knew to be easier. “Any notion that there is generous grading at the top end is a serious problem for the IGCSE,” he says. “Our main worry now is the idea of the generous grading story - it’s a big risk.”

Most independent school leaders say they give their heads of department the choice to pick between the IGCSE and the reformed GCSE based on the merits of the course (although they expect schools will increasingly move to the new GCSE as it matures).

Ed Elliott, head of The Perse School in Cambridge, says a big attraction of the IGCSE is the fact that it is a known quantity.

“One of the reasons a lot of independent schools have stayed with IGCSE is because it’s stable,” he says.

Shaun Fenton, head of Reigate Grammar School and chair of the Headmasters’ and Headmistresses’ Conference, agrees. He compares the caution shown by private heads over the new GCSE to recent comments by the skills minister, Anne Milton, who said that she would advise her children to “leave it a year” before taking the new T-level vocational qualifications.

“Is it a surprise then that independent schools are only cautiously adopting a new assessment and awarding programme for GCSEs when potentially that’s what the government minister is saying she would do?” Fenton asks.

Elliott suggests that the latest row about IGCSEs could be motivated by cynicism about the fee-paying sector. “People will look suspiciously at what we do,” he says. “It looks like privileged institutions are doing very well and helping already privileged children to become more privileged. Of course, that’s a very simplistic assessment.”

The fact that this argument is taking place at all is extremely telling. In part, it is a reflection of the complexity of the UK exam landscape. “It’s not just an IGCSE-GCSE issue,” says Elliott. “We’ve got Northern Irish GCSEs, we’ve got Welsh GCSEs, we’ve got English GCSEs. There’s scope for all kinds of divergent standards and grading, that is going to make life much more complicated for people like universities and employers who are having to try to compare qualifications.”

And those comparisons do matter. Despite the exam boards’ protestations, the concerns about fairness persist. The government set out to create tougher qualifications with the new GCSE, and the exam boards that provide IGCSEs have, in many people’s eyes, failed to make the case that their qualifications are equally challenging.

Private schools choosing the IGCSE can pick and choose qualifications with the right balance of coursework and exam assessment to suit their pupils, and when those pupils sit their exams they can make use of anthologies in certain subjects.

The clearest inequity of all is the fact that some universities are asking for higher equivalent grades from students taking the GCSE, compared with independent pupils sitting IGCSEs. That is something that only higher education admissions officers can sort out. But exam boards may also need to act and engage more with the education sector and the public at large if they want to banish the cloud of mistrust surrounding IGCSE.

As Elliott says, they need to “lift up the bonnet”, so the public can be “reassured that things are basically pretty similar”.

“Otherwise this whole story will keep running, students will become demoralised and schools will become worried.”

@whazell