by political editor Paul Francis

Nearly 50 schools in Kent are without a head teacher - while others are having to advertise up to five times to fill positions.

County education chiefs say the figures for Kent reflect the national trend, but they have prompted a warning the authority is facing a crisis.

Details of the shortage come in a report that also reveals a third of teachers who have quit cite bullying and harassment by senior staff as a reason for going. More than half do so because of disruptive pupils.

Cllr Martin Vye, opposition Liberal Democrat spokesman on education at KCC and pictured left, said: "It is a major problem.

"I think we are approaching a crisis situation in getting people to put themselves forward and getting people of the right calibre. I am particularly concerned about schools in some of the most disadvantaged areas who are facing enormous challenges."

Small primary schools found it particularly difficult, he added.

According to a report due to be presented to county councillors on Thursday, of the 49 schools without a head, 20 have stand-ins while the rest have either an executive head - meaning they may be in charge of other schools - or are being led by a department head.

The shortage will be worrying as it is generally accepted a school's performance is closely allied to how well it is led.

The difficulties schools face recruiting replacement head teachers is reflected in other figures recording the times they have been forced to advertise the vacancies.

These show that in 2011, 29 schools failed to appoint a head teacher first time and were forced to re-advertise the position.

In the case of one, the post had to be re-advertised five times before a suitable candidate was found.

Currently, 21 schools in the county are advertising or about to advertise head teacher vacancies - all but two being primaries.

KCC says while new heads get help initially, there is "insufficient focus on mentoring and coaching for teachers and leaders throughout the system".

Kent is also facing problems finding teachers prepared to stay in the county as their careers develop and turnover in newly-qualified teachers who often leave schools in challenging areas more quickly.

"Newly qualified teachers attracted to schools in areas of high deprivation are frequently the less well qualified... stronger graduates who begin their career in areas of high deprivation do not stay long. They tend to be ambitious and gain promotion quickly."

The report also highlights evidence suggesting many who leave Kent do so because of the lack of support they get developing their leadership roles.

Cllr Mike Whiting (Con), cabinet member for education at KCC, said: "We have a number of initiatives planned for the coming months to make sure we address the anticipated need for new headteachers, senior leaders and teaching staff.

"We will be providing opportunities for existing teachers to train for headships and continuing our work with Canterbury Christchurch University to bring through the next generation of teachers."

Unions said they are unsurprised by the figures.

John Walder, the secretary of the Kent NUT, said there was a reluctance among many to apply for headships because of the pressure and interference.

"There was a time when heads were left to get on with the job. Now they have a whole host of people on their shoulders looking at what they are doing and that is a disincentive.

"What I hear from them is that they are fed up with it. They are in the firing line for anything that goes wrong - if the Sats results or GCSE results do not come up to scratch, they get the blame."

He added the pressures on teachers had been made worse by league tables.