Almost two dozen complaints were made following Ofsted school inspections in Surrey over the last three years, new figures show.

Last month, the watchdog launched a consultation seeking the views of parents, school staff and childcare professionals on a range of proposals aimed at improving its inspections.

The National Association of Head Teachers said it has "real concerns" about the way Ofsted's inspection reports are carried out, and warned the new proposals may put a strain on "already overburdened" inspectors.

A freedom of information request by RADAR shows 20 complaints were sent to Ofsted following school inspections in Surrey between the 2021-22 and 2023-24 academic years, including five last year.

Of all complaints sent in the last three years, three were partially upheld.

Across England, a total of 1,018 complaints were submitted, with the number of complaints increasing by 60% over the last three years, from 248 in 2021-22.

Nationally, 17 complaints were upheld, while 216 were partially upheld.

However, a teachers' union has criticised the lack of an independent body to investigate Ofsted complaints.

Complaints can be made during or after an inspection to raise concerns about the inspection or its outcomes and are dealt with by the watchdog itself.

Paul Whiteman, general secretary of the NAHT, said: "It is simply unacceptable for complaints to be dealt with internally by the very body that is being complained about.

"In fact, there are likely many more schools experiencing problematic inspections than these figures reveal, as school leaders fear they may not be dealt with fairly if they do complain."

Mr Whiteman said the NAHT is calling for the implementation of "a fully independent complaints mechanism to adjudicated inspection complaints", adding the union has "real concerns" regarding the way Ofsted's inspection reports are carried and handled.

In December 2023, an inquest found an Ofsted inspection "likely contributed" to the death of head teacher Ruth Perry, who took her own life in January of the same year after the watchdog published a report downgrading her school from its highest rating to its lowest over safeguarding concerns.

Following this, Ofsted rolled out a series of adjustments to improve its school inspection process, and last month launched a consultation seeking the views of parents, school staff and childcare professionals to reform the school inspection and assessment model from this autumn.

The consultation lays out several proposals such as introducing report cards to parents, focusing on disadvantaged and vulnerable children, and returning to schools where issues were raised to verify action is underway to make improvements.

It also suggests replacing the current 'single word' marking system with a colour-coded five-point grading scale, providing schools with ratings for each area of practice under proposals for Ofsted’s new report card system.

But the NAHT has "grave concerns" about the proposals, warning it will put a strain on "already overburdened" inspectors and result in "more insecure judgements and unacceptable inspector conduct".

Mr Whiteman added: "The unequal power relationship between the inspected and the inspector drives a dynamic that is genuinely dangerous to health.

"Even leaders that receive good inspection outcomes describe being broken by the adversarial and attritional nature of inspection."

Pepe Di’Iasio, general secretary of the Association of School and College Leaders, said reforms to Ofsted's inspection model "could exacerbate the problem", with the five-point grading system likely to increase "inconsistency and unfairness".

Mr Di’Iasio added the number of complaints made to the watchdog following school visits is "an indictment of an inspection system which many school leaders regard as being punitive, unfair and inconsistent".

"If anything, it is the tip of the iceberg, as there are almost certainly more leaders who do not make a formal complaint because they don’t think it will change anything," he added.

An Ofsted spokesperson said: "We want our inspections to raise standards of education for all children. Our new report cards will provide better information for parents and be fairer and more balanced for schools.

"We would encourage everyone to give us their views and respond to the consultation."

A survey of more than 800 parents by non-profit organisation More in Common, commissioned by digital newspaper Schools Week, found 65% preferred the proposed new "report card" system to the previous model, with only 16% who said they preferred the current marking system.

But a poll of more than 11,000 teachers by app Teacher Tapp found only 24% thought the new rating system would be "somewhat fairer" than the current one.