PTI Chairman Imran Khan on Wednesday alleged that PPP Co-chairperson Asif Ali Zardari was behind a plot to bribe his party's MPAs into switching loyalties ahead of the upcoming chief minister's elections in Punjab.

"Today Lahore is seeing a repeat of the Sindh House horse trading that happened in Islamabad with up to Rs500m being offered to buy MPAs. The main architect behind this is Asif Zardari who gets NRO (national reconciliation ordinance) for his corruption and purchases people with looted wealth. He should be jailed," the former prime minister tweeted.

Imran said that attempts to purchase MPA loyalties were not only an attack on democracy, but also on society's moral fabric.

"Had SC (Supreme Court) taken action & debarred these turncoats for life it would have acted as a deterrent. Don't handlers of US regime change conspiracy's imported govt realise severe damage being done to the nation?" he questioned.

Imran's claim followed similar allegations made a day earlier by other PTI leaders, who said the party's MPAs were being threatened and pressurised by the government through intelligence agencies and police to ‘manipulate’ the voting.

Meanwhile, PTI leader Shahbaz Gill alleged today that an MPA of the party was "bought" by Zardari and the PML-N for Rs250m.

He said that on Imran's instructions, a protest has been called at Lahore's Liberty Chowk today against the alleged horse trading.

Meanwhile, addressing a press conference in Islamabad, PTI Vice President Fawad Chaudhry alleged that a party MPA from Rahim Yar Khan, Masood Majeed, had fled to Turkey after being bribed with Rs400m. He accused Zardari of being behind the ploy.

Chaudhry said that three more MPAs had submitted their affidavits to the apex court, explaining how they were offered bribes. He also accused PML-N leader Attaullah Tarar of being involved in the alleged attempt to bribe PTI MPAs.

"We don't know how many MPAs have been approached. No person who is involved in such tactics will ever be forgiven by people. This habit of sticking to power should now end."

Tarar denies, levies counter-allegations

Shortly after, Tarar held a press conference of his own and rejected all the allegations levelled against him.

He challenged Chaudhry to testify his claims on oath on the Holy Quran, saying he would leave politics forever if Chaudhry did so.

Regarding the PTI leader's claims about the Rahim Yar Khan MPA, Tarar said that Chaudhry Masood Ahmed had resigned in April and lambasted the opposition party for not being aware of its own members.

"This crying of yours, I understand why it is being done," he said, adding that more resignations could possibly come forward.

Tarar levied his own counter-allegations of PML-N MPAs being allegedly bribed by Punjab Assembly Speaker Parvez Elahi and his son Moonis Elahi.

Tarar said a PML-N lawmaker was approached with a bribe of Rs100m while he was performing Haj. He further alleged that Moonis was "pleading" with the MPAs in Islamabad to switch loyalties while an elderly female PML-N MPA was also approached in Faisalabad.

Tarar said if the matter escalated to the courts then the PML-N would also present "all evidence".

Sindh Information Minister Saeed Ghani also issued a strong response to Chaudhry's comments, decrying them as "false and absurd".

He said Chaudhry's comments signalled that PTI MPAs were themselves not willing to vote for Parvez for the chief minister election and the PTI was trying to blame others for its internal squabbles and inability to manage its members.

Additional reporting by Imtiaz Ali.