As performance-related pay for teachers is introduced in increasing numbers of countries around the world, policy-makers have stressed the positive impact the reform can have on student achievement.
But a widespread survey of school leaders in England and Wales, where the system is due to be introduced from September, suggests that teachers themselves will see little benefit.
Performance-related pay has gained traction globally and is being adopted in Sweden, Portugal, India and parts of the US, among other places. But in the first analysis of the likely impact of the controversial overhaul in England and Wales, just 3 per cent of school leaders said their staff would receive more money in their pay packets as a result of the reforms.
A survey of almost 900 principals, deputies and assistant headteachers - carried out by TES and the Association of School and College Leaders (ASCL) - has found that the majority of school leaders (51 per cent) expect fewer teachers in their school to receive a pay rise after the change. A significant minority believe it will make no difference or are still unsure of the impact.
The idea is designed to bring automatic pay rises to an end, with schools given the flexibility to offer higher salaries to their best teachers. Brian Lightman, general secretary of ASCL, said that most of his union's members had "no problem" with performance pay in theory, but warned that tight budgets meant only a minority of schools could afford to take advantage of the new freedoms. "If we are going to be able to pay better teachers more, we have to put more money in the budget," he said.
"The reality of the current situation is that if you want to pay somebody more, you have to pay somebody else less. That is unfair. You have to put money in to make it work and make pay about performance rather than affordability."
This view is backed up by George Parker, former president of the Washington Teachers' Union, who became the first US union leader to agree to the introduction of performance-related pay in 2010. He has argued that the approach makes "perfect sense" and last year told TES that "the teacher who puts more effort and more time into getting better results deserves to be rewarded".
However, he also insisted that additional funding should be contributed to allow schools to pay their best teachers more. In Washington DC, pay reforms mean that the average teacher salary is $77,000 (pound;46,000), the highest in the region. According to District of Columbia Public Schools, 11 per cent of teachers working in its most challenging schools were eligible for the largest pay rises in 2012.
Despite the concerns over how many teachers will actually benefit from the reforms, 42 per cent of secondary school leaders who responded to the TES-ASCL survey said the pay changes would have a positive impact on their schools.
The UK government has claimed that the reforms will make teaching "a more attractive career". But they have been opposed by classroom unions, with a national strike next week by the NUT expected to disrupt thousands of schools.
A report published earlier this year by thinktank Policy Exchange says that introducing performance-related pay will effectively force poorly performing staff to "improve or exit the profession". But the report - which draws on international evidence - also warns that schools will have to make "difficult decisions", including denying rises to some staff.
Delegates who attended the Global Education and Skills Forum in Dubai last weekend - which included politicians, educationalists, charities and businesses - were asked whether they thought teachers should be paid based on their performance; 76 per cent said yes.
But Martin Freedman, director of economic strategy at the Association of Teacher and Lecturers, said: "Fundamentally, there is no more money for schools to offer pay rises." He added: "It's not the best teachers that are being rewarded, it's the lucky ones who are in the right place at the right time."
A Department for Education spokesman said the reforms would allow school leaders to "pay great teachers more". "It is pleasing that so many heads are so supportive of this policy," he added. "More top graduates [are] entering the profession than ever before and vacancy rates are at their lowest for eight years. These changes will further raise the status of the profession and encourage more great people into teaching."