The new Accelerate to Headship programme has been developed by the National College for School Leadership, which was asked by ministers a year ago to devise a course to enable teachers to become heads in four years.
But the finer details of the course, which starts next spring, have come as a surprise to heads' unions, who say they were not asked about it officially.
A consultation by NCSL about the standard of school leadership ended on Monday and attracted just 200 responses from 23,000 schools.
The idea of another scheme to encourage high-flyers to take charge of schools has been broadly welcomed by unions, provided it gives new entrants sufficient training to be successful in the job.
Mick Brookes, general secretary of the National Association of Head Teachers, said: "It's important this course covers how to work with a school community. It's not enough just to know about teaching and learning and those who don't have this knowledge will struggle in the job.
"It's a shame the Government didn't talk this through with their social partners."
John Dunford, general secretary of the Association of School and College Leaders, said he did not think heads would be experienced enough with just four years' training, and was pleased the course would also be open to assistant heads and deputies.
"Four years to become a deputy head is acceptable and a significant number of teachers get there in this time," he said. "I don't know if this course is needed."
Its predecessor, the Fast Track scheme, which has cost at least Pounds 89 million since its launch in 2001, has resulted in only 176 people being recruited to headships or deputy headships.
Accelerate to Headship will start with a rigorous assessment and selection process. Participants will have to complete a "stretch" assignment, either in school or elsewhere, and complete a project in school to help it to improve.
They will also spend time in business schools, universities, large firms and charities.
By the third year of the course, teachers will have to start the now mandatory qualification for headship, the NPQH.
How long it takes
20 years: average time for a teacher to become a head.
4 years: time taken for entrants to the Accelerate to Headship scheme to become a headteacher.
3 or 4 years: undergraduate teacher training, either BA with qualified teacher status or a BEd.
2 years: Registered Teacher Programme, a combination of work-based teacher training and academic study for those without a degree.
1 year: PGCE programme, graduate teacher programme or school- centred initial teacher training. But teachers must then complete an NQT year.
6 months: length of initial training on the Government's new fast-track scheme.
6 weeks: length of intensive training undertaken by Teach First staff before they go into schools, although it is two years before they are considered fully qualified.