Stephen Kershaw, director of the school workforce division, said analysis of 14-year-olds' test results south of the border suggested that there is four times as much variation in performance within the one school as there is between schools.
"When we talk about what makes the difference, is it being in a good school as opposed to not a good school? That makes much less difference than what happens to you within whatever school you are in. It's whether individual teachers are good at the job," he said.
Mr Kershaw said it was down to teachers' pedagogic skills and how well they were managed and challenged. It depended on the quality of their initial training, how well they kept up their professional development and how much they collaborated and learned from good teachers.
Addressing the first joint conference of Scottish and English education directors in Newcastle, he revealed only about a fifth to a quarter of the difference in pupils' performance may be attributable to the school they attend. "The real difference is made within the school and made by individual teachers," he said.
Mr Kershaw, who is responsible for modernising the profession in England, forecast a stronger push on performance-related pay to reward good teachers. Higher salaries could also go to teachers working in the south-east where recruitment is difficult, to those in shortage subjects and in particularly disadvantaged communities.
The workforce director reinforced the message that teachers were no longer working in isolation in the classroom and would increasingly depend on collaboration with colleagues and a new breed of support staff. In England, some 50,000 extra support staff would soon be in place to take the strain off teachers. In Scotland, the equivalent figure under the McCrone agreement is 3,500.
Mr Kershaw said research had shown that only about a third of teachers'
time was spent on direct teaching. The rest was on preparation, planning, assessment, administration, supervising and covering for absent colleagues. But many duties could be taken by differently qualified staff who might deal with technical matters, behavioural problems or financial management.
Scotland was tackling professional modernisation from the alternative McCrone route, although the aims were the same, Philip Rycroft, head of the schools' group in the Scottish Executive, told directors.
Mr Rycroft said Scotland was "making good progress" and that it was "a little frustrating for all involved" to hear that the national agreement was constantly unravelling. It had delivered on pay on time, 2,000 probationers were in place, numbers of support staff were rising, and all teachers had a 35-hour week, helping to tackle workload.
Further, the revised Scottish Negotiating Committee for Teachers had agreed new disciplinary procedures, a new framework for professional development and had scrapped the dated Schools (Scotland) Code.