Pakistani Prime Minister Shaukat Aziz insists the government will go ahead with a decision to deport foreign religious students.
Foreign madrassa students say their studies are peaceful
The move was announced by President Pervez Musharraf last week as part of a campaign against extremism.
Religious schools (madrassas) as well as senior government supporters are urging the government to reconsider.
The schools have been in the spotlight after one of the London bombers was reported to have studied at one.
Prime Minister Aziz spelt out the government line on ending the visas of foreign religious students in comments to journalists late on Friday.
"This is a firm decision," he said.
The day before, Chaudhry Shujaat Hussain - who heads the main party in the government, the Pakistan Muslim League - urged President Musharraf to reconsider the move.
The government estimates that there are about 1,400 foreign students attending madrassas in Pakistan.
President Musharraf said he took the decision because he did not want the madrassas "misused for extremism".
The ruling has been widely condemned within the country.
Maulana Wali Khan, a spokesman for the Wafaq-ul-Madaris, which controls about 10,000 madrassas, said: "We knew that he would take this step to appease America and other Western nations."
Foreign students at madrassas insist they are not an extremist threat.
It is still not known when the policy will come into force.