Sixth-formers who are given unconditional university offers are more likely to drop out when they reach higher education, according to new figures.

Universities regulator the Office for Students has found that students who accepted an unconditional offer are 10 per cent more likely to drop out of their undergraduate course than if they had taken up an offer with conditions attached.

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The OfS found that hundreds of students who were expected to finish their studies are dropping out during the first year of their degree.

The watchdog said it was concerned by the data, warning that admissions systems are “not fair and not working in students’ best interests”.

School leaders agreed, saying that students need to be encouraged to choose courses suited to their ambitions and interests rather than those for which they receive unconditional offers.

The OfS analysis covers 18-year-olds in England’s universities and colleges and shows the recorded drop-out rate for students who accepted unconditional offers was 7.08 per cent.

Using modelling, the regulator estimated that the drop-out rate would have been 6.44 per cent if these unconditional offers had been replaced with conditional ones.

So, based on those calculations, their drop-out rate was 10 per cent higher for students who accepted unconditional offers than would have been expected if they accepted conditional offers.

The analysis said that across the 2015-16 and 2016-17 academic years, this equated to 185 fewer students continuing with their studies.

If these patterns continued, and the rates of unconditional offers made continued to rise, more than 200 students a year who would have been expected to continue their degree studies could drop out, the OfS said.

Recently there has been growing concern about the prevalence of unconditional offers - where students are guaranteed a university place, regardless of their A- level grades or other qualifications - as well as the use of “conditional unconditional” offers in particular.

This is when a student is given an unconditional place on the condition that they make a university or college their firm first choice.

In April, then education secretary Damian Hinds wrote to 23 universities, calling on them to end the practice of making such offers to students.

And in September, current education secretary Gavin Williamson called on universities to do the same.

Some fear this leads to sixth-formers putting less effort into their studies and underperforming in their exams as a consequence.

In 2012 and 2013, less than 1 per cent of university applicants held at least one unconditional offer, but by 2018, this had risen to nearly one in four - 23.7 per cent.

The latest figures suggest that as of the end of June this year, more than 24.5 per cent of applicants held at least one unconditional offer.

OfS chief executive Nicola Dandridge said: “We already know that students who receive an unconditional offer are more likely to miss their predicted grades at school. It is a cause of real concern that they are also more likely to drop out of university once they get there.

“Drop-out rates are overall low in England, so this is a small effect. But we are not talking about one or two students - this is a couple of hundred students per year who have made a significant investment of time and money in a degree from which they are unlikely to benefit.”

Ms Dandridge said some unconditional offers were necessary, but “many are not”.

“What we are seeing here are admissions systems that are not fair, and are not working in students’ best interests,” she said.

Geoff Barton, general secretary of the Association of School and College Leaders (ASCL), said: “This analysis provides further evidence that the excessive use of unconditional offers is not in the best interests of students.

“We are particularly concerned about so-called ‘conditional unconditional offers’ where the offer is made on the condition that the student makes the university their first choice.

“These offers encourage students to sign up for courses which are not necessarily the best choice for them and this is probably why they are then more likely to drop out.

“To make matters worse, the use of these offers can also demotivate students when they are taking their A levels and other post-16 qualifications, leading them to do less well in these important qualifications.

“We would encourage students to choose the university course which best suits their interests and ambitions, and we would urge universities to desist from the practice of making this type of offer.”

A Universities UK spokesperson said: “There are clear benefits in universities being able to use a variety of offer-making practices to reflect an individual student’s circumstances, potential and the context of their application, and to support different groups such as students from disadvantaged backgrounds.

“An important principle of the UK system is that universities decide independently which students they accept; but with this comes a responsibility to explain why and how places are awarded, and to show the public and students why different types of offers are made.”