More than 1.7 million pupils who are vulnerable, or whose parents are key workers, may be asked to return to school as early as next week, while ministers are targeting June 1 for a wider reopening of primary schools. 

However, headteachers have now urged ministers to clarify whether attending schools will be compulsory or optional after restrictions are eased. 

Usually, parents could face fines of £60 if their children are absent from school with no good reason, which then doubles to £120 if not paid within 21 days.