Fewer than half of university applicants believe their predicted grades accurately reflect what they would have received if they had sat the exams as planned this summer, a survey suggests.

Nearly a third of applicants say they now feel less confident that they will get a place at their chosen university amid the coronavirus pandemic, according to a poll by a think tank.

The findings, published by the Higher Education Policy Institute (Hepi), came after this summer’s GCSE and A-level exams were cancelled in a bid to slow the spread of Covid-19.

Teachers in England have been told to provide the grades they think pupils would have been most likely to achieve if exams had gone ahead. The judgments will be based on a full range of evidence – including classwork, coursework, mock exams or previous results.

School staff will also rank their students within each predicted grade for each subject. Schools are not allowed to tell pupils or parents the grades submitted until final results are issued.

The survey, of 506 UK university applicants and 1,039 undergraduate students, found that 46% of applicants expect their predicted grades to reflect their final grade – but more than a quarter (27%) think their predicted grades will be worse than if they had been able to take exams.

It is clear applicants need greater certainty about what will happen to their university places

Nearly one in three applicants (29%) feel less assured that they will get a place at their preferred university due to the pandemic.

If pupils are unhappy with their grades, they will have the opportunity to sit exams at the start of the academic year. But this could be too late for students who want to start university this autumn.

A separate poll, published by Ucas last week, revealed that 5% of school leavers are planning to sit their A-level exams in the autumn term.

Rachel Hewitt, Hepi’s director of policy and advocacy, said: “It is clear applicants need greater certainty about what will happen to their university places.

“It is essential this group, who have already lost out on the end of their school experience, are not disadvantaged from getting into the university of their choice. The data shows this is a concern for a significant minority of applicants.”

Jo Grady, general secretary of the University and College Union, said: “University applicants are already suffering from a turbulent end to their current stage of education and need support as they move on to university. It is not business as usual at the moment and it is unlikely that everything will have returned to normal by the start of the new academic year.

“We need to provide support and safety nets so students are not disadvantaged by the coronavirus crisis. We want guarantees from universities that students who decide to appeal their results or resit exams can hold their university place while they go through that process.”

Claire Sosienski Smith, National Union of Students (NUS) vice president for higher education, said: “There is still a lot of uncertainty over the application and admissions process for students applying to university this year, and it’s a real concern that a significant proportion of students think that their predicted grades are lower than their final grades would have been.

“We must work to ensure that students are graded fairly, and that the routine under-prediction of BAME students does not leave a generation of students shut out of opportunities.”

On students’ concerns, Geoff Barton, general secretary of the Association of School and College Leaders, said: “This anxiety is understandable in the context of such huge upheaval but we would reassure them their teachers know them well and the process of centre-assessment being used this year will be as fair as possible.”

The survey, from Hepi and YouthSight, also revealed that more than a third (36%) of university students believe their assessments this year should be cancelled amid the pandemic. But more than two in five (42%) want universities to continue their assessments online.

It found that just under half (49%) of students are satisfied with the online learning that has replaced their face-to-face teaching, compared with 23% who are dissatisfied.

But the vast majority of students (70%) said they feel the messaging from their university on coronavirus has been clear.

A Universities UK (UUK) spokesman said: “Decisions, including those concerning admissions, must continue to be made fairly, consistently and in the best interests of students.

“UUK has confidence in the way A-levels will be awarded this year and will support Ofqual as they continue to develop their precise methodology.

“Students can be reassured that universities will be flexible in taking an applicant’s context into account as part of the admissions process. No student should feel rushed into a decision at what is already a difficult time for them.”

Education Secretary Gavin Williamson said: “Cancelling this summer′s exams was a necessary step to help fight the spread of coronavirus by asking people to stay home, protect the NHS and save lives.

“Despite the difficult circumstances we are facing, the latest guidance provides assurance to students, parents and schools that grades awarded this summer will accurately reflect students’ abilities and will be as valid this year as any other.”