By political editor Paul Francis

County council chiefs are calling for urgent talks with the secretary of state for education Ed Balls after he announced plans to send in "troubleshooters" to help Kent’s poorest performing secondary schools.

County council leader Paul Carter has written to Mr Balls saying his move is at odds with what Kent County Council has been told about the progress it is making in lifting classroom standards at 33 schools which are part of the National Challenge initiative.

But his letter also reveals that GCSE results at five of the schools on the Government’s list unexpectedly fell this year. The schools are not identified.

Under the scheme, the Government says all schools must achieve 30 per cent of pupils securing five or more GCSE passes at grades A to C, including maths and English, by 2011.

Kent has the highest number of such schools and the Government says it is concerned that not enough progress is being made to reach its target.

In his letter, Cllr Carter says that while results at five unnamed schools "unexpectedly dipped" this year KCC was well aware of what needed to be done.

"Not only did 11 of our National Challenge schools exceed the 2011 target this year, but another 11 are now within four per cent and are well placed to achieve this in 2010. Of the remaining 11 schools in the National Challenge, six have improved and we feel are on track to meet the 2011 target, some with structural solutions already under way. Five schools unexpectedly dipped this year. The local authority, the school leaders and their national challenge advisers are in no doubt as to the reasons and the solutions, and we will be collectively focused on driving further improvement."

Meanwhile, KCC’s opposition Liberal Democrat group said Kent’s selective system meant schools were chasing unrealistic targets.

Education spokesman Cllr Martin Vye said: "Kent’s selective system clearly leads to a situation where some schools have greater challenges to face and getting to this target is going to be extremely difficult. Schools can always do better but the dice is loaded against them, particularly with the leeching out of children to grammar schools."