A-level students who attend poorly-performing schools should be given extra credit by universities, a report said.

The paper for one of the country's biggest exam boards is being handed out at party conferences to encourage politicians to discuss ways to get pupils who show academic potential at weaker schools to continue with higher education.

Dr Neil Stringer from the Assessment and Qualifications Alliance (AQA), the author of the report, said research suggested students from "more favourable circumstances" were matched academically by their less privileged counterparts at university.

The senior research associate at the exam board's Centre for Education Research and Policy used the example of a medical school at the University of London that offers lower A-level grades to pupils from poorer schools.

St George's offers results of BBC rather than AAB to students who perform 60% better than the average for their school.

Dr Stringer said: "St George's reports that students from poorly-performing schools who are accepted into medical school with lower grades do just as well as their peers with higher grades.

"This strongly suggests that students admitted through the adjusted-criteria scheme learned enough at A-level and are able-enough learners to compete successfully with students who achieved higher A-level grades under more favourable circumstances."

Schools minister Nick Gibb said: "Universities are in charge of deciding their own admissions policies.

"But this proposal risks confusing employers, teachers and pupils by giving different values to the same A-levels and would undermine the integrity of public exams."

"All pupils who work hard and achieve high standards deserve to have their qualifications recognised."