, has created further alarm among teachers' leaders already concerned by the strength of the Government's push for chains of state schools.
Association of School and College Leaders general secretary John Dunford said it was a "shotgun measure" and "not the right way to go".
The white paper says that to improve performance in their own school and to "deliver outcomes for the wider community", school governors need "to be open to the possibilities and rewards of partnership, executive headship and federation".
"A particular time when all governing bodies should consider such arrangements is before beginning the process of recruiting a new headteacher, and we will set out in secondary legislation that all governing bodies must consider federation andor sharedexecutive leadership at that point," the document says.
Phil Revell, chief executive of the National Governors' Association, gave "100 per cent" backing to the principle of considering the future of a school when appointing a head.
But Dr Dunford said: "I don't think that the appointment of a head is necessarily the right moment to consider those kind of partnerships, which should be entered into for their own sake, not simply as a reaction to a fear that a governing body might not be able to appoint their own head."
Primary schools might need to consider federating because of a lack of potential heads, he said. But new laws were not needed to provide encouragement, which would usually come from their local authority or church diocese.
For secondary schools Dr Dunford said: "A shortage of heads is not an issue. The question of whether to federate is a more strategic consideration, not made on the basis of headteacher appointments."
The white paper unveiled the concept of "Accredited Schools Groups" - chains of schools run by "good education providers" - as part of a general push for more partnerships between schools.
In the run-up to the paper's publication, Schools Secretary Ed Balls warned of consequences for schools that chose to "go it alone".
"If you are a school that has got the potential to do this (collaborate) but chooses not to, you're not making a contribution to other schools in your area," he said. "Therefore Ofsted will recognise you aren't being as ambitious as you could be."
But the schools watchdog later said it would not judge schools on their willingness to participate in mergers, federations or chains although they would be assessed positively if they were leading to better "outcomes" for pupils.
The paper says that school governors can trigger Ofsted inspections if they have concerns about performance or reforms introduced by a new head.
The Government also wants all governing bodies to be supported by trained clerks, and says that all chairs of governors will be expected to go through specific training for the role.
Mr Revell backed all three measures but said the training should be mandatory for all governors.