What would you do if you found out a senior member of staff was cooking the books, that staff appointments were bypassing equal opportunities guidelines, or there were phantom pupils on the school roll? Most people turn a blind eye to minor wrongdoing, but school staff may feel they should tell someone if they believe pupils’ education is being undermined, public money is being diverted or people are using their connections to land plum jobs.

The decision to blow the whistle is never an easy one. “Grassing up” a colleague or your boss feels risky, and the outcome is impossible to predict. The authorities may prefer not to receive the information, but if you believe someone is doing something that is damaging the school, following the right procedures will give you the best chance of having the issue dealt with effectively.

The Public Interest Disclosure Act (Pida), which came into force in 1998, encourages employers to respond to the message rather than the messenger, and to resist the temptation to cover up serious malpractice. The act makes it unlawful to victimise an employee who raises legitimate concerns that malpractice has occurred or is likely to occur, even if the whistleblower turns out to have been mistaken, as long as the person had a genuine belief that wrongdoing was going on, and followed the disclosure procedure. The act aims to promote the public interest - to ensure, for example, that public funds are not misspent - by supporting those who speak out when things go wrong.

When whistleblowing works well, we don’t hear about it: the authorities address the problem, the whistleblower feels vindicated, and the organisation is better off as a result. But when the system lets people down - if the authorities try to cover up malpractice or silence the whistleblower - the employee’s role in exposing corruption, fraud or the abuse of power becomes even more significant.

Guy Dehn, director of Public Concern at Work, a charity that advises whistleblowers, says: “Employees usually raise a concern because there is a problem that needs to be sorted, and the only real criterion for success is whether or not it is sorted. But you also have to take into account what happens to that person in the process.”

Janet Cooper (not her real name), a former secondary school bursar, discovered financial irregularities in her school’s budget. She reported it to the Funding Agency for Schools, which, until 1998, oversaw budgets for direct grant schools, and her actions led to a police inquiry and government intervention. Ms Cooper describes what happened next: “I had spent five years as a respected member of the senior management team, but when I refused to go along with what the head was asking, I was pilloried and intimidated.” She believed she had no choice but to resign. With the backing of her union, Unison, Ms Cooper became one of the first people to use the Pida. She took her employer to an industrial tribunal and, just before the case was due to be heard, the school governors offered her an out-of-court settlement of pound;10,000. There was just one problem: the compensation payment would have had to come out of the school budget - the very one she had acted to protect.

Ms Cooper refused to take the money and ended up in a low-paid, part-time job. Three years later, she has now found a full-time job, and believes she has a chance to put these experiences behind her. “It was upsetting; it takes over your life and you feel very vulnerable. But I’d do the same thing again because you can’t not speak out when you believe something is wrong.”

Mr Dehn says: “Whistleblowing is like a barium meal for the system. It can be unpleasant but it reveals whether or not the system can deal with malpractice in a fair and effective way. In education, the lines of accountability can be confused and diffused, but cases like Janet’s open that up to scrutiny.”

Teachers at Hanover primary school in the London borough of Islington became tangled up in just such “confused and diffused” lines of accountability almost two years ago, when they handed their chair of governors a dossier of allegations about their headteacher, Cynthia Thumwood. The most serious of these concerned tampering with SATs papers.

What followed was a tortuous process in which the teaching staff, who had acted unanimously and in good faith, were left feeling frustrated, unsupported and exposed as the buck was passed around.

The Qualifications and Curriculum Authority annulled Hanover’s key stage 2 SATs results and the school lost its beacon status. The QCA says its brief is to determine how far the tests represent the children’s work, and not to suggest who might have interfered with the papers, even if forensic evidence points to one particular person.

Cambridge Education Associates, the private company that runs Islington’s schools, says: “Proper procedures were followed and an investigation was initiated. The governors decided that no disciplinary action should be taken.” The chair of governors strongly disagrees, saying CEA dragged out its investigations, leaving him “frustrated, isolated and in a ludicrous situation”. Without the support of their LEA, the governors felt unable to take action.

Cynthia Thumwood continued to protest her innocence, but retired earlier than planned. CEA then installed an interim head for two terms, and staff morale hit rock bottom. One of the teachers says: “I thought, ‘this is even worse. Have we done the right thing?’ We had reported something we believed to be wrong, and believed something would be done to put it right. It was always a whole-staff decision to blow the whistle, and not one person has changed their mind, but we were made to feel as if we were troublemakers.”

Nevertheless, Hanover has retained all its staff, who now feel positive about the future and are proud that the school and its ethos are still intact. Guy Dehn says: “The teachers paid a heavy price but they should see the outcome as a success. They wanted to protect the school and its values and they have done that. What’s more, like Janet Cooper, they all say they would do the same again. Perhaps, with hindsight, they might have done some things differently, but at the outset their main concern was to protect the school, and that’s what they’ve done.”

Mr Dehn says employers need to create a culture in which employees can raise concerns at an early stage and know they will be dealt with before they generate the kind of anxiety and distress these and other teachers have suffered. Those in authority should welcome the chance to deal with malpractice instead of wanting to hide it. “These difficult cases, painful as they are for the individuals concerned, demonstrate the importance and value of whistleblowers, because they have shown the authorities that the system must be accountable and open to scrutiny.”

If you are worried about malpractice in your school, contact Public Concern at Work, an independent charity. Tel: 020 7404 6609; email: helpline@pcaw.co.uk; www.pcaw.co.ukindex.html

BEFORE YOU BLOW THE WHISTLE...

* Compose yourself and try to stay calm

* Think about the risks and outcomes

* Remember you are a witness, not a complainant

* Remember there may be an innocent or good explanation

* Avoid becoming a private detective

* Never use a whistleblowing procedure to pursue a personal grievance

* Don’t expect thanks

Useful contacts

* Department for Education and Skills. Tel: 0870 000 2288; fax: 01928 794248; email: info@dfes.gsi.gov.uk; www.dfes.gov.ukindex.htm

* Financial Services Authority. Tel: 020 7676 9200; email: whistle@fsa.gov.uk; www.fsa.gov.ukwhistle

* Governorline: 08000 722 181 (Monday to Friday, 9am to 10pm, weekends 11am to 4pm)

* Qualifications and Curriculum Authority, 83 Piccadilly, London W1J 8QA.

Enquiry line: 020 7509 5556 (Monday to Friday 9am to 5pm); fax: 020 7509 6666; minicom: 020 7509 6546; www.data.teachers.org.ukindex.html

* Teacher Support Line, supported by the unions and funded by the DfES: 08000 562 561; www.teachersupport.info