Coltart said most of the teachers, who taught maths and english, had gone to Botswana and South Africa.
He said poor salaries and working conditions were the main reason for the exodus of teachers, leaving local schools unmanned.
"We have lost over 20,000 teachers since 2007. In South Africa, an entry teacher earns about R8000 (about US$978), which (is) not commensurate with what local teachers are getting," he said.
Zimbabwean teachers get an average of US$150 per month, which is woefully inadequate.
Only teachers at private schools, which are few in the country, receive better pay.
Zimbabwe is drafting a new higher education Act aimed at enhancing the quality of education and training after years of neglect. But the proposed legislation has been condemned by student representatives, who say its provisions show that the country’s new inclusive government is not serious about tertiary reform.
The draft Zimbabwe Qualifications Authority Bill, which is expected to be tabled in Parliament in the coming months, will repeal the Higher Education Examinations Council and the Zimbabwe Schools Examination Council Act.
The new legislation will create a Zimbabwe Qualifications Authority that will oversee the development and administration of a Zimbabwe Qualifications Framework, whose objectives will among things be to improve educational quality through competency-based learning. The authority’s functions will include establishing education standards and qualifications.
The new authority will be overseen by a board comprising of between 15 and 28 members. The draft law says the board will be appointed by the education minister after consultation with the President and "in accordance with any directions" the President may give.
Previously, lawyers have claimed that provisions allowing direction by Zimbabwe’s leader have been abused by President Robert Mugabe and used to punish his opponents and silence dissenting voices.
With Mugabe still President, albeit in a power-sharing arrangement with the former opposition Movement for Democratic Change led by Morgan Tsvangirai as Prime Minister, students are jittery about laws allowing presidential direction.
Clever Bere, president of the Zimbabwe National Students Union (Zinasu), complained that students were not consulted during drafting of the proposed law: "This shows that there is no reform in terms of how the inclusive government is conducting its business. How can they come up with a higher education policy or law without consulting students? That cannot be tolerated," he said.
An indication of the new government’s insensitivity to student aspirations was the creating of a board for the Zimbabwe Qualifications Authority with no student representation, he added.
Bere said students were also not happy about the way the new government was handling the process of creating a new constitution.
The government recently announced a 25 member parliamentary select committee, agreed between Mugabe’s Zanu-PF party and Tsvangirai’s MDC, that would spearhead the crafting a new democratic constitution to replace the current one that gives Mugabe wide executive powers and imposes no limit to the number of years a person can rule the country.
"As students the current constitutional process falls short of our expectations as it is parliament-driven and not people-driven. At the moment we are watching from the sidelines but we will hold a general council in due course to decide the way forward," said Bere.
The students’ position on the constitution is similar to the one adopted by the rights group, the National Constitutional Assembly, NCA. Its chairman Dr Lovemore Madhuku, a law lecturer at the University of Zimbabwe, said last week the NCA would campaign for a ‘no’ vote "because any document that comes from a defective process is defective. We are going to start a campaign opposing this process. We will obviously be holding demonstrations."
The government’s latest snubbing of students in formulating policy shows that students were wrong about the conclusions they reached at a consultative forum held on 18 March under the title "Exploring the Opportunities and Prospects of Higher and Tertiary Education Reforms in the All Inclusive Government".
They concluded that the inclusive government would create opportunities for students to be consulted in the creation of a curricula, for education to become accessible and affordable for most students, and for alternative education policies to be created.