Saeed, blamed by India for masterminding the 2008 Mumbai attacks, has addressed gatherings and rallies across Punjab since he was released from house arrest last year but had not visited Islamabad in the recent past.
Addressing the gathering, Saeed stressed the need for a well-organised media campaign in favour of the blasphemy law.
Former premier and senior Pakistan Muslim League -Q leader Chaudhry Shujaat Hussain also attended the meeting, which called for a countrywide strike on December 31 to oppose moves for changes in the blasphemy law.
A death sentence given by a lower court in Punjab to a Christian woman, Asia Bibi, convicted of insulting Prophet Mohammed has triggered a debate on the need to repeal or amend the blasphemy law introduced by late military ruler Zia-ul-Haq in the 1980s. The law carries a death penalty for anyone convicted of using derogatory language against Islam and the Prophet.
Minority communities and rights groups have said that the law has been misused to falsely implicate people in blasphemy cases.
An official report on Asia Bibi's case submitted to Pakistani President Asif Ali Zardari said she had been framed in the case. Zardari has asked Minority Affairs Minister Shahbaz Bhatti to recommend reformed procedures to prevent the misuse of the blasphemy law for personal and political reasons.
During Wednesday's meeting, the leaders of the main religious parties announced they would resist any move to amend the blasphemy law.
Jamiat Ulema-e-Islam chief Maulana Fazlur Rehman, who presided over the meeting, called for a strike across the country on December 31 to oppose moves to change the law. Rehman said rallies will be organised in major cities on December 24 and a major rally will be held in the port city of Karachi on January 9. The future strategy of the religious parties will be announced at the Karachi rally. He also asked the government to clarify its position on the issue.
The leaders said they would raise the issue in parliament and oppose any move by the government to table amendments in the law.
Saeed said he would support the movement by the religious parties.
