Justice T Raja said the school education department issued the impugned order on December 3, 2009, and that it could not be applied retrospectively on candidates who had joined D.Ed courses in Karnataka in 2008.
By the time the order was issued, the candidates concerned would have had completed their first year of the course, the judge said, adding that a batch of petitioners who had approached the court against the order were about to write their final second-year examinations.
The Tamil Nadu government said it was constrained to keep out D.Ed-holders from Karnataka, as the syllabus in that state had not been updated in tune with the National Curriculum Framework, 2005.
While Tamil Nadu had updated its syllabus for teacher education courses, Karnataka still had curriculum of 2002, it said, adding that the order was issued to maintain quality of education in Tamil Nadu.
He, however, said giving retrospective effect to the decision would prejudice the accrued rights of candidates, and added as per the principle of 'promissory estoppel' these candidates cannot be denied their entitlement.
The judge asked authorities to consider if the D.Ed certificates obtained by the petitioners from the Bangalore colleges were equivalent to the teacher education degree in Tamil Nadu or not.