Montessori and Steiner organisations are concerned that reform of training for early-years workers could leave practitioners with their qualifications unrecognised.
The Children's Workforce Development Council (CWDC) has said it wants to simplify qualifications for early-years workers by providing one relevant qualification.
It launched its new diploma for the children and young people's workforce in September 2010, saying it should be the only qualification that counts when calculating staff-child ratios in early-years settings.
There will also be an official register that recognises existing qualifications, so that those already working do not have to retrain.
But Steiner and Montessori groups are angry that teachers who take their qualifications in the future will have to take the new diploma as well if they want to be recognised.
Barbara Isaacs, academic director at the Montessori Centre International, said: "We found out that we are not offering a recognised qualification and of course we have protested.
"We provide diversity and provide things parents want for their children. Our current qualification meets all the required criteria. The CWDC itself mapped it against national occupational standards."
About 800 people are currently training to be Montessori teachers.
Officials from the CWDC and the Department for Education are due to meet with Montessori and Steiner organisations in May following the publication of the Tickell review of early-years education this week.