The National Association of Headteachers wants school articles of government changed to limit governors' ability to take disciplinary action against staff.
It says the case of Joe Peacock, head of Belah primary school in Carlisle, Cumbria, shows why changes are needed. The union and the county council were this week seeking legal advice over Mr Peacock's suspension three weeks ago following allegations by the chair of governors. The NAHT may also appeal to Secretary of State Gillian Shephard to overturn the decision.
The union claims the allegations are groundless and is demanding the head's immediate reinstatement and an apology. The council, which advised the governors not to suspend the head, has warned that the school may have to pay if there are any financial consequences.
An inquiry has begun and a result is expected within three weeks.
The NAHT warns that governors are increasingly using their power to suspend staff with immediate effect. David Hart, the NAHT's general secretary, said: "One of the fundamental issues this raises is whether the existing wording found in articles of government and other disciplinary documents should be changed.
"It is possible for people to be suspended on wholly inadequate grounds merely because the governors say it is urgent. We are concerned about the tendency to suspend first and ask questions later and this is a classic example.
"Every case like this brings the existing procedures into disrepute and underlines the need to reword articles of government to make sure circumstances in which people can be suspended are made much clearer," added Mr Hart.
Derek Marbeck, a regional NAHT officer, added: "Joe has been treated disgracefully. There is no substance in the allegations and he has an excellent record as a successful, popular head, yet his career has been thrown in the ashcan. An increasing number of governors are taking precipitate action of this kind. It damages stability and means the children are the real losers."
James Adshead, who has two children at the school, said: "Joe has won enormous respect and most parents are horrified at what has happened. The children's confidence has been undermined by rumours sweeping the school."
Harry Slater, Cumbria's senior education officer, said: "We advised the governors that we do not think suspension is appropriate, but they have the power to do this despite our advice. We are continuing to keep the matter under review and reserve the right to reconsider the legal status of this matter. "