LONDON (Reuters) - Schoolchildren in England will not sit formal exams this year due to the coronavirus pandemic, education minister Gavin Williamson said on Wednesday, with teachers to assess students and decide their grades instead. England entered its third national lockdown on Tuesday, shutting schools and shops and ordering citizens to stay at home as a surge in cases of a new coronavirus variant threatens to overwhelm the healthcare system. Williamson said exams for 14 to 18 year olds - used to determine entry to colleges and university - would be replaced by teacher-assessed grades. “Although exams are the fairest way we have of assessing what a student knows, the impact of this pandemic now means that it is not possible to have these exams this year,” he told parliament. Earlier this year Williamson was widely criticised for relying on an algorithm to determine students’ grades. He was forced to abandon the system after flaws produced unfair results for some students, affecting their admission to universities. After a public outcry, the algorithm-determined results were replaced with teachers’ predicted grades where students felt they had been marked too low.