New Education Secretary Nicky Morgan has been urged to avoid trying to "mark (her) mark" with "another raft of reforms" upon replacing Michael Gove.
Brian Lightman, general secretary of the Association of School and College Leaders (ASCL), stood apart from other leading education unions in paying tribute to the departing Education Secretary.
"As someone who has had extensive contact with Michael Gove I have absolutely no doubt that he has a passion for improving the life chances of young people," he said.
Yet Mr Lightman added: "Many of his reforms have been highly controversial and time will tell what the impact is."
More top news
Photos from a historic day in Scotland's history as voters choose to remain part of the United Kingdom.
Is Manchester really more powerful than Wales and Northern Ireland? Find out how the union's four nations compare with England's regions.
Hollywood director J.J. Abrams has been declared the victor in a good-natured Twitter war with his friend and fellow director Zack Snyder.