When Michael Gove decided to let academies and free schools employ unqualified teachers, furious teaching unions accused the education secretary of causing "irreparable damage to children's education". Now Mr Gove's coalition partners in the Liberal Democrats have joined the fray and called for the regulations governing teacher qualifications to be reinstated to protect the professionalism of teachers.
All teachers should be qualified or working towards qualified teacher status (QTS), members of the party have said. Delegates are expected to adopt this as official Liberal Democrat policy for the first time at their spring conference later this month.
Members of the party hope to reverse the decision to give academy and free school headteachers freedom over who they employ, made by Mr Gove last summer.
"Because we are in a coalition we have to compromise, but this is clearly the Liberal Democrat position," said Baroness Brinton of Kenardington, a member of the party's Committee on Education, Families and Young People. "A reversal isn't something that could be done overnight, but it is something we would want to work for because it is critical for children and teachers."
Baroness Brinton said adopting the policy would give Liberal Democrat schools minister David Laws a stronger position from which to argue. It would also be something that could be debated with potential coalition partners after the next general election, she added.
Academy and free school leaders were told that the relaxing of QTS regulations meant they could hire "brilliant people" who were not trained teachers and that this would help them to improve their schools.
The change gives state schools the same freedoms as schools in the independent sector to hire staff with specialist skills, the Department for Education said. Professor Alison Wolf, who reviewed vocational education for the government, said it should make it easier for schools to hire industry experts to support work-based learning.
But John Howson, vice-president of the Liberal Democrat Education Association, said that the motion to reinstate the need for QTS would "send a message to the Tories".
"It will please teachers and it gives David Laws a bargaining chip. We take a different view, that the most important thing is teachers ought to be trained," he said.
James Noble Rogers, executive director of the Universities' Council for the Education of Teachers, said that all teachers "should have recognised teaching qualifications".
"Parents should have the right to expect teachers to be properly qualified," he said. "It's not enough for the government to say most schools will make sure their staff are properly trained - this should be enshrined in legislation."
The motion to be debated at the Liberal Democrat conference also proposes opportunities for working sabbaticals and job exchanges between schools, and "sustained study" to help teachers fulfil their "personal career aspirations".
Brigid Tullie, headteacher of Batley Grammar School near Leeds, employs one unqualified teacher, a subject leader for geography who is a Cambridge graduate. She said the relaxing of the regulations allowed school leaders to employ "gems", even though they were not qualified.
Mary Bousted, general secretary of the ATL teaching union, criticised the Liberal Democrats for what the party had "sacrificed for the trappings of ministerial power".
"They must be ashamed of the fact that, when their party entered coalition, the legislation was rushed through with indecent haste, which established QTS was not needed in academies and free schools," she said. "It's too late now. The cat is out of the bag."
A Department for Education spokeswoman said: "We have given academies the same freedoms the best independent schools enjoy to hire the great linguists, computer scientists, engineers and other specialists they know can best teach and inspire their pupils. While we expect the vast majority of teachers will continue to have QTS, this additional flexibility will help schools improve faster."
Schools free to hire teachers who do not have QTS (as of February 2013):
2,055 converter academies
618 sponsored academies
80 free schools.