New Delhi, August 5: Over 600,000 posts of teachers at primary level are lying vacant under the state sector and the national literacy mission, parliament was informed Monday. "The total teachers post lying vacant at the primary level both under the state sector and the Sarva Shiksha Abhiyan are 6,06,191," Human Resource Development Minister Smriti Irani told the Rajya Sabha in a written reply. "The states recruits teachers based on their recruitment rules. However, teachers who are appointed have to possess requisite qualification prescribed by the National Council for Teacher Education (NCTE) and pass the Teacher Eligibility Test (TET)," she added. Irani said that the recruitment of teachers on contract basis, therefore does not affect the quality of teaching adversely as all teachers recruited have to meet the educational qualification as well as professional qualifications. "However, professional qualifications are sometimes relaxed under section 23 of the Right of Children to Free and Compulsory Education (RTE) Act, 2009 for states where there is a shortage of professionally qualified teachers, with the provision that they acquire the same through a two year training programme in distance mode," she said. Irani also informed that the pupil teacher ratio (PTR) has improved nationally to 1:25 and most states barring Bihar, Jharkhand and Uttar Pradesh have normative PTRs.