The PPP on Friday rejected the tax amnesty scheme revealed a day earlier by the prime minister, vowing to oppose it in parliament.
Former Senate chairman Raza Rabbani, while addressing a press conference in Karachi, lumped the new scheme with the PML-N government's previous schemes, all of which, he said, had failed.
"It is unfortunate that in this government's tenure, all of the schemes were for the benefit of capitalists, big businesses and the ruling elite of Pakistan," Rabbani said, adding that none benefited the middle classes and the poor "who have been crushed under the burden of direct and indirect taxes, and inflation."
If the government chooses to bring an ordinance regarding the amnesty scheme to the parliament, "it would be a strange and surprising thing that the parliament would be asked to give blanket [immunity] to all black businesses."
He said that he would request the PPP's parliamentary party and, if he gains its approval, ask the opposition's parliamentary party to reject the ordinance under Article 89 of the Constitution.
"In at least the Senate, the opposition should bring a resolution for disapproval of the ordinance," Rabbani said.
When asked about whether his party was considering challenging the move in courts, he said: "I think we should try to resolve political issues through parliament rather than going to the courts."
He also rejected the claim that the new scheme would adversely affect the illegal hundi business in Pakistan. There are other ways to curb the practice if the government is really serious about it, he maintained.
Prime Minister Shahid Khaqan Abbasi, after a meeting of the Economic Advisory Council on Thursday, had announced tax reforms aimed at clamping down on tax evaders and expanding the tax net.
He had also announced that those who avail the scheme will be given a one-time exemption allowing undeclared assets held locally or abroad to be declared after payment of nominal penalties.
Pakistan Tehreek-i-Insaf chief Imran Khan had immediately rejected the scheme saying such measures are "created to benefit the corrupt" and have never worked in Pakistan.