Concerns that more grammar schools are likely to consider setting their own eleven plus test have prompted county education chiefs to change plans for a replacement exam.

Kent County Council had set out proposals for a new test, designed to reduce the scope for private coaching.

It was planning to offer a three-year contract to run it.

There has been growing concern a widespread private coaching culture giving those who can afford tutoring an unfair advantage in the competition for places, especially in west Kent.

However, the council now says it intends to invite tenders for a one-year contract - partly to see if more of the county's grammars choose to run their own admissions tests, as they can if they are academies.

Already, some grammars operate separate tests in addition to the county-wide exam as a way of allocating places. It is thought more are considering doing so.

Education chiefs say that not being tied to a three-year contract will allow the authority flexibility to adjust "at a time when secondary schools are increasingly looking at whether to run their own tests."

Privately, Kent County Council is concerned separate tests by different schools will only add to the pressure on children and may itself lead to more coaching.

However, it also claims a renewable one-year contract could permit changes to the exam to be made that limits the potential for coaching.

Education cabinet member Cllr Roger Gough (Con) said the new test would be sat by pupils in 2014 and changing to a one-year contract meant Kent County Council would not be tied in.

"While schools can organise and run their own tests, I still believe that a single test reduces the stress and pressure on pupils and their parents.

"For this reason, I will continue encouraging schools to use the Kent Test as the measure for selection - ahead of offering places for Year 7."

Around 13,500 children sit the eleven plus each year for places at Kent's 33 grammars each year.