Calling for Ofsted to be abolished could risk “squandering” a real opportunity for change, the sister of Ruth Perry has said.

Professor Julia Waters has called on unions to focus on “working constructively” with the inspectorate following the death of her sister.

Her comments came after delegates at the annual conference of the National Education Union (NEU) voted for a “public facing” campaign calling for Ofsted to be abolished to be launched by the union.

The motion, which was passed at the union’s conference in Bournemouth on Wednesday, also called on the NEU to advise its members to “refuse to work” as Ofsted inspectors until “full reform has been implemented”.

It comes after Ofsted has come under greater scrutiny after the suicide of headteacher Ruth Perry.

Mrs Perry took her own life after an Ofsted report downgraded her Caversham Primary School in Reading, Berkshire, from its highest rating to its lowest over safeguarding concerns.

But Prof Waters, who is due to address the NEU’s conference on Friday morning, said: “I agree wholeheartedly with everything the NEU is trying to do to improve school inspection, right up to the point when they call for Ofsted to be abolished.

“Yes, the system needs fundamental reform. Teachers and headteachers are still facing intolerable pressure from inspections. This cannot be helpful to children or parents.

“But, while understanding the strength of feeling, I do not believe that calling for Ofsted to be scrapped helps anyone.

“The current government won’t do it, a future Labour government wouldn’t do it. So why waste the energy and risk squandering the current opportunity for change?”

Last month, Sir Martyn Oliver, chief inspector of Ofsted, launched the watchdog’s Big Listen public consultation that will seek views about Ofsted.

In his first major speech since becoming chief inspector in January, Sir Martyn said he wanted to “mark a new chapter” with the sector, adding that “nothing is off the table”.

The motion, which was passed on Wednesday and mentioned Mrs Perry, called on the NEU executive to encourage “the removal of all mention of Ofsted judgements in publicity material”.

It also called on the union to support members in “balloting for, and taking, strike action” when “mocksteds”, deep-dives and excessive workload have arisen through Ofsted pressures.

Findings from a survey of NEU teacher members in England, released at the conference, suggested that 82% believe a new system of inspection should be introduced because Ofsted has “so many problems”.

During the debate, delegate Ian Walters, from Derby, described Ofsted as a “ruinous regime” and he said he had witnessed a number of “rude and intimidating inspectors” over the past 20 years in the profession.

Addressing the conference, he said: “Ask yourself how many of your colleagues have been seriously impacted by Ofsted? How many have left the profession? In many cases losing talented, dedicated professionals as a result of their experiences at the hands of this menace to education.”