A new network of hand-picked headteachers will help the Government to investigate the effect of individual teachers on pupil performance.

Some members of the 250-strong leadership network, set up by the National College for School Leadership, have already started projects aimed at reducing the big variations in the performance of pupils in the same school.

School standards minister David Miliband has said that within-school variation is four times greater than that between schools, and that teachers account for 30 per cent of the difference.

Twenty heads met this week with Professor David Reynolds of Exeter University, who has been asked by the Department for Education and Skills to conduct the research. It is a sensitive area, but Ray Tarleton, the network’s national co-ordinator and head of South Dartmoor community college, Devon, does not mince his words.

“We have moved from the ‘no blame’ culture to one of accountability, and it’s one we have to accept now. There can’t be any excuses. Children matter.”

He added: “If the DfES could solve the issue of why pupils perform differently with different teachers, it would have a world-class education system.”

The network, which was set up a year ago to promote innovation, promises to be equally forthright and pragmatic with its other new ideas for policy-makers.

Its policy proposals over the next five years includes a three-year sixth-form; replacement of paper-and-pen exams by online testing; initial teacher training delivered by schools, not universities; and performance tables which reward innovative schools for helping other schools, their communities, or the education system nationally.

Mr Tarleton, seconded to the job for two days a week and nine regional co-ordinators appointed in April, have drawn on the best ideas of members nominated by education authorities, the DfES and others for their work.

At its first annual conference this week, addressed by Professor David Hopkins, head of the Government’s standards and effectiveness unit, members complained that the DfES was unable to keep up with its own school-based initiatives.

Heather Du Quesnay, the college’s chief executive, told delegates: “We need to influence policy but it doesn’t matter if we are not entirely successful as we can change things ourselves - by our multiple interventions.”

Carole Whitty, a former head and senior adviser at the DfES, said: “We are being invited to seize the debate as professionals and to be part of the education revolution. Being part of this network recognises us as potential policy-makers in our own right.”

The headteacher associations are sanguine about whether the network, which they helped to set up, will challenge their influential position with government.

David Hart, general secretary of the National Association of Head Teachers, said: “There is room for everyone in this debate. No one who has a good idea should be excluded.”