The council is considering fining parents who let their children bunk off school after new Government figures revealed truancy rates for the borough's primary schools was getting worse.

Out of all the half days when children were absent from the borough's primary schools last year, 0.67 per cent were unauthorised.

This means that pupils aged between five and 11 were absent without permission.

The figure for 2005-2006 is a 0.04 per cent increase on last year and Croydon is one of 22 London boroughs with primary truancy records that are showing no sign of improvement. The average unauthorised percentage for England is 0.46 per cent.

Schools in London faired the worse in the truancy chart, averaging 0.76 per cent, with only eight London boroughs improving on last year.

Two of Croydon's neighbouring boroughs, Lambeth and Merton, improved on last year - although Sutton's figures also slipped.

General secretary of the National Union of Teachers (NUT) Steve Sinnott, said that "parental connivance" was a factor as parents were taking children out of school to go on holiday or for shopping trips. He added: "The increase in the proportion of primary pupils truanting has to be nipped in the bud."

A spokesman for Croydon Council said an unauthorised absence did not always equate to a child truanting in the streets.

"Because schools are tightening up as part of the general crackdown the local education authority is having on attendance, they are not authorising absence as easily as they were, which is why there has been a short-term rise in unauthorised absence.

"Overall, however, the attendance figures last year were largely due to the winter vomiting illness which struck Croydon schools very hard in the spring term."

The spokesman added: "The LEA will also be investigating ways of reducing holidays in term time - both by the use of penalty notices and other enforcement measures but also by publicising the damage that a holiday in term time can do to a pupil's education and by working with the DfES and local travel agents to promote deals which encourage parents to take their holidays in the school holidays."