The truancy rate in England's schools has increased by two per cent, latest figures show.
Statistics published by the Department for Education reveal that the "unauthorised absence" rate for the autumn and spring terms of 2010/11 stood at 1.03%, up from 1.01% for the same period in 2009/10 - a two per cent rise.
The figures are for state-funded primary and secondary schools.
The truancy rate stood at 0.97% for the autumn/spring terms of 2006/07, meaning it has increased by 6.2% in five years.
Around 64,500 pupils of all ages skipped school sessions without permission on a typical day in the autumn and spring term through truancy, family holidays, illness and other reasons, an analysis of the figures suggests.
In primary schools alone, the truancy rate rose to 0.69% from 0.68% for the same period in 2009/10.
And in secondary schools the truancy rate stood at 1.41%, up from 1.4% the year before.
The most common reason for absence was illness, the figures show.
But family holidays accounted for 9% of absences, and 2.54% were for family holidays that were not agreed by the school.
Today's statistics show that almost half a million children (450,330) missed 15% of school in the autumn and spring terms - the equivalent of more than a month of lessons in a year.
Children who miss 15% of school time are considered "persistent absentees". In the past, children who missed 20% of lessons were considered to be in this category.
More than a million pupils missed 10% of school time - the equivalent to missing a half day or more of school a week, the figures suggest.
Schools minister Nick Gibb said: "Today's figures reveal the worrying extent of absenteeism in our schools.
"It is unacceptable that more than 450,000 pupils are missing the equivalent of a month of lessons a year. Even one day missed from school without very good reason is one too many.
"Children who are absent for substantial parts of their education fall behind and struggle to catch up. By lowering the threshold, we are encouraging schools to crack down on absence before the problem escalates."